I am experiencing a similar problem but only to a few selected devices:
Tm-1900 converted to AC68U as the main router
- Asuswrt Merlin AND/OR AiMesh firmware, various versions (all behave the same)
I have a Linksys E2500 running on Tomato and in wireless bridge mode. With/without mac address filtering, it works fine.
I also have a Linksys WRT310N running on Tomato and in wireless bridge mode. With/without mac address filtering, it works fine.
However, I have a Linksys EA6900 running xvortex firmware. Trying to set it up in wireless bridge mode: without mac address filtering it works fine, but with, NO. I previously reported this here:
https://www.snbforums.com/threads/media-bridge-not-working-on-both-ac68u-ea6900.42666/
I would love to get to the bottom of this as I prefer to turn on mac filtering.
regards,