Also, the phone reboots from time to time (not frequently - once in a week or so).

There is now a solution for this issue.
In a terminal, type

setprop persist.vendor.ssr.enable_ramdumps 0
setprop persist.vendor.ssr.restart_level ALL_ENABLE

For more details see at :
https://forums.ubports.com/post/77507

the GUI has lags during starting of apps and between switching apps

For more info see : https://forums.ubports.com/topic/9621/x-lomiri-touch-true-can-cause-lags

@Boldos said in Poco X3 NFC:

Also, the phone reboots from time to time (not frequently - once in a week or so).

There is a workaround : https://forums.ubports.com/topic/8855/pin-code-needed-after-a-few-hours/55?_=1701355308586

• the GUI has lags during starting of apps and between switching apps
• the power/thumb reader button is "always on", so any touch activates it.
  Also, the phone reboots from time to time (not frequently - once in a week or so).

Otherwise, the phone is pretty ok to use with 22.04 20.04.