Problem with open site/channel via router with OpenWRT

hello, I have a problem after a few recent updates to the router that has openwrt on it... I noticed it now (somewhere after a week)

Router: Xiaomi AX3600

FW: OpenWrt SNAPSHOT r23375-cdfcac6e24 / LuCI Master git-23.158.78004-23a246e

namely, the problem concerns the slow loading of certain content on the Internet, more specifically tv channels in kodi via port 8880

When I switch the decoder to the Internet from the openwrt router, the channels load in 15-20s which is damn annoying ... when I switch the decoder to the hotspot from the phone (where LTE Internet is) the channels load in a second..

It seems as if the router was blocking the connection with the decoder in some way

I don't know how to describe it in a search engine but can you help how to make the router with openwrt so that the specific IP address (decoder) was not checked by the firewall/NAT at all, but flowed without any blocks to the Internet.

Or maybe is other way to repair this ?

waiting for response