I’m late to the party here.
XA2 Plus.
I have been seeing this problem for a very long time, but it never quite bothered me enough to follow-up on it. For me it happens a few times a month. But when it happens, it typically happens a lot.
For a while, switching to the front camera and then back to the rear camera works-around it. But eventually, even that fails.
On a good day, the camera takes 10-60 seconds to start. Although I don’t think that that was the case when the bug first appeared.
A restart usually (always?) fixes it for me.