SXT Lite5 with ubnt-APs problem

Hi,
I am using Ubnt Loco.M5 as AP connected to RB2011U Mikrotik server.
my clients have been using SXT Lite5 to connect through my APs since two years, and now I am receiving a lot of problems( no connectivity, connecting and disconnecting..etc)
the SXT was setting was "station WDS ". when the problem of no wireless connectivity came up, I modified the mode to “station pseudobridge”, but even though, I am still receiving problems especially with some Samsung mobiles like Samsung J7.
I think the problem is behind the latest mikrotik update “v6.39.2”
my settings for SXT Lite5 is:
Wireless
Wireless Mode: station Psedobridge
Band: 2GHz-A/N
channel Width: 20MHs
SSID: my SSID
Wireless Protocol: 811.2
scan list: 5000-6000
Frequency Mode: superchannel
HT
AMPDU Priorities: 0,1,2,3,4,5,6 selected
that’s it
Please help
Thanks

any answer?

There is not enough information about your configuration and network topology for anyone here to give you any specific answer.
Please provide more details and if possible exports (without sensitive parts like passwords etc.) from all of
your Mikrotik routers in data path from the end clients to your ISP.

Regards,
M.

p.s. Why are you using UBNT AP and Mikrotik’s CPE units (SXTLite5)? The only way they can work together is pure 802.11 and that is not an optimal mode for neither of them.