Home assistant can talk to all my devices except one?! (ping, ssh http) everything else can reach it just fine!

Hi all,

I am around a week into trying to figure out this weird issue.
I recently have bought a nodeMCU ESP8266 micro-controller for a project which i have set up and have running on my network perfectly. Now that its up and running, everything in my network can talk to it EXCEPT my home assistant?

I have home Assistant running on a Pi3B+ working perfectly fine. I am unable to ping the Module from HA, but I can happily access it from every other device on my network (which can all talk to HA). I know the routes are correct in HA and work for all other devices.

I have uploaded an image that shows my network setup (2 subnets, HA+device in same subnet) i have included some examples of where i can and cant access the device.

Does anyone have any advice? i expect it must be something HA specific given everything else works fine. I have also tried using multiple IP’s, static addresses, dhcp assigned, static ARP , you name it.

Any chance there is something left over in the /etc/hosts.deny file on the Home Assistant pi?

doesn’t look like it unfortunately! that file doesn’t exist for me?
Screenshot 2022-02-13 092311

What are the outputs of

route -n from the pi?