Disappearing 4G and 5G

[SquirrelSpider]

I have this strange problem with my A55 - 4G and 5G disappears multiple times a day and only comes back if I restart the phone. Any ideas? SIM card works alright in other phone.

[BandOfBrothers]

Hello 👋 @SquirrelSpider 

Does this happen in a particular area or everywhere 🤔 I'm thinking maybe network congestion or a mast issue. 

If a phone is dual sim then sometimes trying the sim in the secondary slot can help. 

There is a diagnostic tool found in the Samsung Members App. 

And you can reset the network connection via Settings > General Management > Reset > Reset  Mobile Network Connection 

Clear Cache Files from the phone's System Partition Section  > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop or use a Tv's USB Port or a usb-c to usb-c phone to phone set up to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too { Possibly excluding the s²⁴ Series of phone's } 

A Samsung Service Centre can assess the phone if necessary. 

If i can be of any further help please don't hesitate to ask  😎 

[SquirrelSpider]

I ran the diagnostic tool, it said both SIM and network connection was okay. The issue seems to be random. Sometimes it happens once a week, sometimes twice in an hour. Once 4G and 5G disappears, it doesn't come back even many hours later and even if I go into a different area with excellent 4G/5G. After restart though, 9 out of 10 I promptly have excellent 4G/5G even in the very area where I lost them...

[Piper123]

Hey there

When you lose connection, are you connecting to a WiFi service such as BT WiFi or similar when out and about?

There have been other threads on this, have you searched the forum for any solutions already found?

[SquirrelSpider]

Not usually. What happens usually, is that I have great 5G/4G, then as I walk signal shows weaker and weaker and eventually goes to H+ or H, then it gets stuck on H+ or H. But it's not really poor network. Almost always if I restart the phone right there and then I have good/excellent 5G/4G once again

[Piper123]

Are you on O2 by any chance as the other 3 networks have phased out 3g

[SquirrelSpider]

Yes, O2

[Piper123]

OK so O2 is a weaker network so wondering if there are works going on in your area for example that have resulted in a weak signal currently

[SquirrelSpider]

Don't think so.. It already happened in 8-10 different towns...

[Piper123]

OK that's helpful to know.

So it sounds more like a sim card or device issue.

Please go to:

Settings
Connections
Reset MOBILE network settings

This will reset your network APNs but you won't lose data. Your network O2 will automatically send you new And in seconds and they'll install in the background.