Locus makes smartphone unusable

Today suddenly my phone (Uledone Armor 2 with Android 7, 6GB RAM) brought a lot of app crashes (regular apps that run in the background, nothing fancy. They just crashed without using them.). After my daughter who also has locus Pro on her phone (Samsung M20, Android 10) reported also such crashes of apps that normally run without problems, I began to investigate.

Deleted Google play cache. Did not help.

Restart of phone. Did not help.

Then I found the icon of the Locus Maps Light version changed. Started it and had a look on the UI of version 4. Also compared with the Pro version 3.5.1.

After this, I had no more crashes of apps.

So I took the phone of my daughter, who has not the Locus Map Light version and also deleted Google Play cache and restarted the phone. The phone had still crashes of apps (reproduceable with i.e. WPS office app starting and crashing). So next step was starting Locus Pro 3.51 which has been recently been updated. Got the message about last version 3. Did a small check if locus runs ok. Deactivated Update of Locus Pro in PlayStore, because my daughter doesn't like the UI of the version 4.

After all this, the strange behaviour was also gone on her phone.

I don't know exactly which step or which combinations of steps helped.

But as finally the crashes of apps ended after starting Locus, I suppose there could be a dependency of new Locus versions.