Yes, I already fail in the very first setup…
Here you find some logs filtered on “coap”; does it give some insights?
33519,83: 2023-03-07 16:09:49.525 DEBUG (MainThread) [custom_components.philips_airpurifier_coap.config_flow] trying to configure host: 192.168.178.72
33520,56: 2023-03-07 16:09:49.657 DEBUG (MainThread) [aioairctrl.coap.client] syncing
33521,45: 2023-03-07 16:09:49.668 DEBUG (MainThread) [coap] Sending request - Token: ab51, Remote: <UDP6EndpointAddress 192.168.178.72>
33522,45: 2023-03-07 16:09:49.669 DEBUG (MainThread) [coap] Sending message <aiocoap.Message at 0x7f7d8c7070: NON POST (MID 53513, token ab51) remote <UDP6EndpointAddress 192.168.178.72>, 1 option(s), 8 byte(s) payload>
33522,71: 2023-03-07 16:09:49.669 DEBUG (MainThread) [coap] Sending message <aiocoap.Message at 0x7f7d8c7070: NON POST (MID 53513, token ab51) remote <UDP6EndpointAddress 192.168.178.72>, 1 option(s), 8 byte(s) payload>
33526,45: 2023-03-07 16:09:50.088 DEBUG (MainThread) [coap] Sending request - Token: 09cd, Remote: <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>
33526,94: 2023-03-07 16:09:50.088 DEBUG (MainThread) [coap] Sending request - Token: 09cd, Remote: <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>
33527,45: 2023-03-07 16:09:50.089 DEBUG (MainThread) [coap] Sending message <aiocoap.Message at 0x7f8e2afbe0: CON GET (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 1 option(s)>
33527,71: 2023-03-07 16:09:50.089 DEBUG (MainThread) [coap] Sending message <aiocoap.Message at 0x7f8e2afbe0: CON GET (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 1 option(s)>
33527,144: 2023-03-07 16:09:50.089 DEBUG (MainThread) [coap] Sending message <aiocoap.Message at 0x7f8e2afbe0: CON GET (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 1 option(s)>
33528,45: 2023-03-07 16:09:50.090 DEBUG (MainThread) [coap] Exchange added, message ID: 61289.
33545,45: 2023-03-07 16:09:50.989 DEBUG (MainThread) [coap] Incoming message <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload>
33545,72: 2023-03-07 16:09:50.989 DEBUG (MainThread) [coap] Incoming message <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload>
33545,154: 2023-03-07 16:09:50.989 DEBUG (MainThread) [coap] Incoming message <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload>
33546,45: 2023-03-07 16:09:50.990 DEBUG (MainThread) [coap] Exchange removed, message ID: 61289.
33547,45: 2023-03-07 16:09:50.990 DEBUG (MainThread) [coap] Received Response: <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload>
33547,74: 2023-03-07 16:09:50.990 DEBUG (MainThread) [coap] Received Response: <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload>
33547,156: 2023-03-07 16:09:50.990 DEBUG (MainThread) [coap] Received Response: <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload>
33548,45: 2023-03-07 16:09:50.991 DEBUG (MainThread) [coap] Response <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload> matched to request <Pipe at 0x7f8e2ae4a0 around <aiocoap.Message at 0x7f8e2afbe0: CON GET (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 1 option(s)> with 2 callbacks>
33548,64: 2023-03-07 16:09:50.991 DEBUG (MainThread) [coap] Response <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload> matched to request <Pipe at 0x7f8e2ae4a0 around <aiocoap.Message at 0x7f8e2afbe0: CON GET (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 1 option(s)> with 2 callbacks>
33548,146: 2023-03-07 16:09:50.991 DEBUG (MainThread) [coap] Response <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload> matched to request <Pipe at 0x7f8e2ae4a0 around <aiocoap.Message at 0x7f8e2afbe0: CON GET (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 1 option(s)> with 2 callbacks>
33548,303: 2023-03-07 16:09:50.991 DEBUG (MainThread) [coap] Response <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload> matched to request <Pipe at 0x7f8e2ae4a0 around <aiocoap.Message at 0x7f8e2afbe0: CON GET (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 1 option(s)> with 2 callbacks>
33548,376: 2023-03-07 16:09:50.991 DEBUG (MainThread) [coap] Response <aiocoap.Message at 0x7fa9023430: ACK 2.05 Content (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 2 option(s), 612 byte(s) payload> matched to request <Pipe at 0x7f8e2ae4a0 around <aiocoap.Message at 0x7f8e2afbe0: CON GET (MID 61289, token 09cd) remote <aiocoap.transports.tinydtls.DTLSClientConnection object at 0x7f92aa3490>, 1 option(s)> with 2 callbacks>
33914,85: 2023-03-07 16:10:19.528 WARNING (MainThread) [custom_components.philips_airpurifier_coap.config_flow] Timeout, host 192.168.178.72 doesn't answer, aborting