I have this exact same issue. I also have poor signal strength since the update, and my phone will not get back on the mobile network unless I restart it. Previously I could receive phone calls in my house, now I can only do so outside - once I restart. I have an expensive mini tablet now.
Attached is a screen shot of my phone in safe mode. I have had loss of
cellular network connectivity for an hour now. I have not yet done a hard
reset. Isn't safe mode essentially eliminating the same potential
points-of-failure as a hard reset?
I have been experiencing the same issue ever since the Lollipop upgrade was released. I get zero cell reception in my office and have to reboot my phone every time I leave my office to get a data connection. I have tried toggling Airplane mode off and on to no avail. My device is not rooted.
One of the responses from this or another thread on this subject mentions to try changing "Preferred Network Mode" to LTE/CDMA. I did this and then rebooted (didn't work until after the reboot). It seems to have corrected my issue (I did also uninstall some apps I don't rely on but otherwise no other changes). Note that after another reboot the mode seems to have switched back to Global, but the issue has not returned.
Change "Preferred Network Mode" from Settings > More networks > Mobile Networks > Network mode.
Hey all, I read today (and this makes sense to me) an article that
explained that you should always hard reset your phone when you do an OS
update, which makes sense to me. I always prefer to do clean installs of
new OS's on all my devices. I'll try it and report back.