[UPDATED] Re-login on locked screen like new login to mate

[pezo77]

Hello supporters, I am new here.
My english not too good, but I need help.

I use Mate Desktop on Debian, on my Thinkpad x230.
While a time if the screen locked, and I want to re-login to my mate session (?) for continue using my opened programs, it closes the graphical session on vty7, prints the following error message: "i2c i2c-2: sendbytes: NAK bailout.", then start the graphical login screen. I can enter my login cretitentials again, and then it starts a fresh mate login, fresh desktop, but my programs (what I used and stay opened before screen lock) gone.
I used Debian 10, all packages upgraded. As display manager I use lightdm.
When I try to use gdm3 for logins, the problem gone if lock screen, but if the laptop entered sleep, no way to wake up. So this isn't solution for me.

The Debian (stable) and Mate installed cca 14 moths ago, and it frequently upgraded, and if possible, dist-upgraded.
The problem wasn't coming with dist-upgrade, after that works perfectly. So may something other went wrong.

What can I do for resolve my problem?

Thanks, Zoltan from Hungary


UPDATE: I found a symptoms what mayme important to catch causing: if the screen locking happens with internal screen only (no extended desktop), all things works well as before. When it has VGA and/or MiniDP screen extension, the symptomps coming.
Maybe the problem started not on exact date, but when I start using desktop extension to works from home.

It means for me the following: no unlock has the problem, but the lock do.

So, can I resolve this problem to the lock works well with external monitors too?

[pezo77]

I tried now: when I switch from non-locked GUI to CLI (ctrl+alt+f1), then switch back (ctrl+f7), this causing same: the graphical screen going to black screen with charactered screen, prints the error message, and quickly start graphical screen with logon (lightdm). Then I logging in, a new mate session started.

I think the normal working would be not going to character screen after I switched back to GUI, and I should enter my login information to unlock screen. But happens not this.
(Sorry for my bad english.)

May it helps for where I can search the problem?

[pezo77]

I found new face of problem, so the original post updated.