No general solution to this problem seems available, or at least evident on this forum. I have it on 4.5.0.18 on a newly flashed Xperia 10 III (flashed to 4.4.0.72 and then OTA GUI upgrade to 4.5) and an XA2, which had been upgraded through every release from 3.4 days. I’ve reported the problem in a bug report
but this hasn’t had much response.
There appears to be an outstanding problem with Android app mobile connectivity which has been around a long time now for, in my opinion, so serious an issue.