Can't access home assistant via ethernet

Configuration
1

Hi all.
I’ve a problem that I can’t solve. I’ve changed my modem/router with a newest (LTE) one: with the previous router there were no problems at all. I could access HA from the PC (wired via Ethernet cable), phones via wifi and via Internet (i.e. from work).
After I’ve changed router, I can access HA only via WiFi and via Internet.
From the PC I can ping it, I even use AdGuard as a DNS with filters, but I can’t access the login page or the dashboard. I can’t even access the files using File Explorer (in the past I could do this). If it means something, I’ve opened all the ports on the router for the raspberry with HA, but without luck.

Any help is appreciated, thank you!

2

Maybe router has some firewall blocking connections lan to lan

3

Oops: you edited. I don’t think so… there are no rules other than the ones I’ve set up for home assistant. And I can access a NAS that I have with no problems. (Nas is wired)

4

I’ll add some info. Installed additional components: AdGuard, Advanced SSH and terminal, DuckDNS, File Editor, Home assistant Google Drive backup, NGInx, samba share, Wireguard.