Probably similar to the screen freeze often discussed on together like e.g.https://together.jolla.com/question/225481/xperia-10-plus-ds-random-freezes/
I’ve made calls to random contacts that way - annoying…
In my case the issue disappeared after battery replacement.
I carefully reassemled esp. the screen connector/plug.
And I found, that the battery plug cover wasn’t installed right so this little metal shield was likely pushing the screen from the back all the time.
So the issue is caused by the phone not being properly assemled and if one is willing to remove and reattach the screen it’s most likely mendable.
Cheers