How to make IPTV work on dd-wrt in client bringe mode?

Question

Computer networks

Good afternoon! I've been worrying about this problem for a week, Google searched all over, tried all the solutions that were offered there. I turn to experts, I really hope for your help!
There is such a scheme:
Internet => TL-WR840N NON-dd-wrd (PC1 is connected to it via LAN, the Internet works, IPTV, everything is fine) => TL-WR841ND v7 dd-wrd in Client Bridge (routed) mode (to it connected PC2 Via LAN, internet works, IPTV does not work .)
How to make IPTV work?
Connecting PC2 is a temporary solution for a more convenient setting of this whole action.
Initially, the plan was to connect a set-top box with a TV in another room using an old router in the hope that there would be a more stable signal.
Thank you in advance!