there are two mikrotiks , one gateway by default.
when restart the second router , users lost packets.
I do not understand what the problem is because the default gateway is available at this time.
two routers include a switch in one , the same as the user
That should pretty much be the entire AP configuration except for the wireless settings.
If you want the WLAN to be its own separate IP network, then I recommend setting up a simple /30 point-to-point link between the tile router and the AP - e.g. 192.168.255.0/30 - with 192.168.255.1 = the tile router and 192.168.255.2 being the AP’s address on ether1.
Then connect the AP’s ether1 directly to the tile router on the interface where you configured the IP 192.168.255.1/30
Finally, on the AP, disable masquerade rules and set the default GW to be 192.168.255.1
and on the tile router, set a static route to whatever IP range is the wlan (e.g. 192.168.100.0/24) with the gateway=192.168.255.2
Of course, make sure the tile router will masquerade for the wlan IP range as well as the user1/user2 lan.
Check the MAC addresses of your routers’ interfaces - especially the bridge interfaces and ethernet interfaces.. make sure that they have different MAC addresses, and also make sure that mikrotik2 (the AP) has a different IP address than the tile router. You’re completely right to expect the AP to have nothing to do with user1 and user2 getting to the Internet through the tile router.