Hello,
For about 1-2 months now my Sony Xperia X Compact very often doesn't recognize a SIM card. Only reboot can help (sometimes after reboot it works well, sometimes network appers for only a few seconds and SIM-card disappears again. It seems (but I'm not completely sure) like quick change of network preferred (GSMonly-WCDMAonly - WCDMA/GSM - LTE/WCDMA/GSM) after rebbot makes it more likely for phone to recognize card for some time longer).
It happens pretty randomly, but is much more likely to happen in areas with bad mobile signal (at work, in the country(no LTE, almost no WCDMA, some areas with no signal at all(cold stores)) after about an hour (not immediately!) phone stops to recognize sim-card and after that I just keep rebooting it with a small chance of getting it to work for 10-20 mins (but more likely for 30s), while in the city it usually works much better, sim-card disappears only few times a day).
Even if phone does not detect SIM-card in test menu *#*#4636#*#* signal data is reading (for example -105dBm 35 asu as I'm writing this)
Resetting connection settings didn't help.
Tweaking *#*#4636#*#* settings (as described here) doesn't help.
Factory reset (ads well as Software repair using Xperia Companion) didn't help.
Putting three layers of duck tape over back of a card, to make it thicker for a better contact (as suggested to me at phone repair shop) didn't help.
Phone temperature doesn't seem to play any role (it happens in the pocket as well as on the table).
I don't remember actual dates, but I think the problem started in the last decade of October, while, as I have found out, last release of firmware(34.4.A.2.118) was relesed September, 25 (I guess phone upgraded in October), so could it be a problem with the update?
Where to get the previous version of firmware(34.4.A.2.107 or eallier) for my region(Ukraine)? (or is it okay to install version for a different region?)
Or will it help and is it possible to change the radio module firmware?
Sony Xperia X Compact F5321
Android 8.0.0
Firmware version: 34.4.A.2.118
Current radio module version: 8976-8976.gen.prodQ-00017-39
P.S. I know I'm not the first owner of Sony Xperia with this problem, so I hope the company is going to fix it with the new update or at least give some other solution.
I really liked my compact phone, but with such a huge problem it's not a phone at all. They said me at the repair shop, that connection problems are very common with Xperia devices. Not the best reputation for a brand to have.
P.S.2. I had the problems with mobile connection from the start: it took very long time (more than a minute) for the phone to recognize the network, after it lost it, while other phones do it in seconds.
