one ui problem Note 9

[bagreev_e_l]

I have a problem with One UI on my Note 9. After some time apps in a background mode are closing up even fixed in the multitask mode. How can I fix it?

[BandOfBrothers]

@bagreev_e_l 

Is this affecting all your apps both stock and downloaded or some of your apps ?

Check the apps haven't been chosen to be put in sleep mode after a while. Choose to keep them awake instead.

If needed a Samsung Experience Store or Samsung Service Centre can run a diagnostic test on the phone for you.

[bagreev_e_l]

This affects all apps. I checked the sleep mode. It didn' help. Also, I did reset to factory settings and have the same problems.
I was in Samsung Service Centre in Kyiv. They say they could do nothing