Hi, I need to connect ethernet-only devices to my network in a room with no wire and I need them to be accessible from the existing network.

My current status:

Three hap ac2 devices:
HAP 1: router with internet access and capsman for wifi of HAP 1 and HAP 2 in manager-forwarding mode. Runs DHCP server for 192.168.88.0/24.
HAP 2: wired to HAP 1, runs as a switch and capsman slave to HAP 1.
HAP 3: connected to HAP 2 over wifi in station mode. Runs DHCP client on wlan2, gets IP 192.168.88.111 assigned from HAP1. Runs DHCP Server on bridge for 192.168.66.0/24.

I want the devices in subnet 66 to reach internet and any device in subnet 88. This works ever since I've added a static route in HAP1:
I also want anything in subnet 88 to reach devices in 66. This doesn't work and I can't figure out why.
From a device in subnet 88 I can ping 192.168.88.111 and 192.168.66.1 (the two HAP3 addresses), but not any other device in subnet 66. I have deleted all firewall settings on HAP3 to no effect.

I know I could use wlan in station-bridge mode and keep everything on subnet 88, but that's not compatible with capsman, which I'd like to keep if possible.
Source: https://wiki.mikrotik.com/wiki/Manual:W ... tion_Modes

Can anybody help? What am I missing? This is my first time playing with the routing table in RouterOS, so I expect it's something silly.