@stealth23 Are you using Omada Controller? I also have ER605 and I take a screenshot of the example settings you need:

I'm using ER605 v1 with controller V5.6.3, however I still cannot see the new Stateful ACL option. It seems that tplink hasn't released the new firmware for this router currently. At least we know...

@danilodal1976 EU version CPE can only use DFS channels. Intruction about DFS about DFS

@TazDevilLooney Omada Controller already update Stateful ACL(which I think can fit your requirement), however it's not available in standalone mode, also I don't know if your switch have firmware...

@ARKANE How much speed you should get from ATT? TL-SL1218P only supports 100Mbps in maximum.

@Kosken Have you checked the IPaddress of the switch? I feel like you actually have two tplink switches and just login to wrong switch. To confirm that, you can unplug this 2210P from the router, and...