rb2011uas-2hnd-in access point problem

Hello,
i have an RB2011uas 2hnd device mainly to be used as network access point. My main network il 192.168.1.0/24 and when i first installed this device i used a different subnet for the wifi connection as 192.168.38.0/24 which is routed to the default gateway 192.168.1.1.
For some reasons i need some devices to be connected using wifi in the same subnet as the main network, so i created a virtual AP and joined a bridge with wired ethernet port which has address 192.168.1.246, and of course i put the IP address on the bridge.
Now if i connect my mobile phone to the orignal wifi network (192.168.38.xxx) and try to run speedtest from ookla i get more then 10mb/s upload and download, if i connect to the new virtual AP which is bridged to the main network i get 200-300 kb/s.
WHat am i doing wrong?

thank for your suggestions