I had 2xAC2 at home...one is gw(ap), 2nd AC2 is client with cable pc. I changed ap(gw) today for ax2 and my client don`t want get ip address anymore.I have all interfaces in the bridge with dhcp client in the bridge.
This setup working with AC2 as AP properly.
Now I hade to remove wlan1 from the bridge in the client and setup dhcp client in wlan1, turn on NAT on wlan1 and setup another netwok on the bridge with dhcp server...this setup working but I have another subnet at home (I don`t want it).
Why client AC2 can`t be in the bridge mode with all its interfaces with ax2 AP anymore?
I have ROS 7.8 in AC2 and 7.6 in AX2.

To create transparent bridge between two wired "islands" of same LAN, the wireless leg has to support 4-address mode. WiFi standards don't specify such a mode, so vendors implemented them each their own way (so they are mostly mutually incompatible). This 4-address mode is enabled by setting AP into "ap-bridge" or "bridge" mode and client into "station-bridge" or "station-wds" (the "station-pseudobridge" (two variants) are often useless because they come with lots of gotchas).
You can read more in this article.

Now, hAP ax2 runs wifiwave2 driver which doesn't implement 4-address mode (yet). So devices running this driver can not be part of wireless bridge between two islands. The same would happen if running wifiwave2 on hAP ac2 would be possible (it's not possible due to other constraints, radio chip is fine).

I was confused because radio was connected via pseudobridge e.g but searching ip address.
Is there only way to add subnet in the gw/ap or using NAT at this moment?

station-pseudobridge should work fine with a huge gotcha: DHCP server (sitting on the "master" side of such wireless bridge) has to allow multiple leases to same MAC address. If it doesn't (and many DHCP servers don't), then only first device on the "island side" successfully receive DHCP lease ... and if station device is set to receive IP address via DHCP, then it will almost always be this device which "consumes" the available IP address. So if you have to go with station-pseudobridge (or station-pseudobridge-clone), then you really should use statis IP addresses on the island side (and by "static" I mean hard-coded on individual connected devices, "static lease" on DHCP server won't do).

I'm kind of an optimist and I expect that eventually wifiwave2 driver will support the 4-address mode. Until that moment happens, I suggest you to keep using the two hAP ac2 devices to create that bridge.
If you want to upgrade wireless performance for the rest of wifi devices, certainly use hAP ax2 ... and use ac2 only for bridge (in this case, you can set radio mode to "bridge" and set up dedicated SSID and PSK specific to bridge use).

I have a workroom in my house (without cable connection) where is my PC but NAS is on the 2nd floor with the GW(AP) and 100-150Mb/s via AC2-AC2 over 5G is too slow sometimes for me. I`d like to upgrade using ax.
I`ve tested 2 ax2 on the desk and get fantastic 900Mb/s over 5GHz so my expectations are huge;o).
If the real speed will be 400-500Mb/s I`l be happy...we`ll see soon, I have to configure the 2nd ax2 as client.
I don`t like lost my bridge setup but I want to the higher speed too.
I can setup DMZ for pc in the client radio a it will be half-solution.


Edit: I`ve tested connection between floors with 2x ax and liitle disappointment...only 300Mb FD in 2.4 or 5GHz but it seems I`ll let installed ax and ac2 will be stored.