Having the same issues on the S21+ upgraded from the S10+. Same network and completely different signal strengths and speeds on LTE/4G. Just sent it back for a replacement to rule out any hardware issues............
This is interesting if both variants have the issue - definitely suggests poor Samsung firmwares. It is probably an 'achievement' that Samsung can introduce the same issue to two different chipsets! Doh!
For me this is definitely an issue effecting upload rates more so, downloads are impacted but less so and not so noticeably.
If you are sat on a cell tower with excellent signal I suspect you will not notice this issue at all. It seems to come in when you have an average to poor signal. Saying that I wouldn't consider low -90dBm to be that bad. I sit around -106/109dBm and upload is almost non existent - and yes I do mean I can't upload at all..! My S10+ and S20+ does/did not have this issue at all.
Keep on at Samsung about this. I think it's a bigger issue that we first thought and it's just that most people aren't using 4G that much right now. End of lockdowns will be very revealing. I hope Samsung are readying themselves.
@Duke Will be very interested to know what you find - I think you're the first to request a replacement over this issue (on this forum anyway). Sadly, I think it won't be different, although I would like to be wrong and find I just have a bad phone.
I will ofcourse post my findings to see if this resolves my issues at least. I have the tech ref also for any Samsung employees that bother to troll and for future. I have an error report raised detailing the issue which is awaiting reply.
This is a move of shear desperation as I suspect its firmware related also. (hopefully not inferior hardware........)
Might start digging around GSM Arena for a different phone entirely.......
Sorry to hear that, but it seems obvious that it is a software issue. I turned off 5G and it is slightly better on the usability, but it is not a solution.
I think we are muppets for tolerating such a crappy product at launch though. Samsung know they will always get away with it though so they treat us with total contempt. We should all return our phones if they don't deliver on our expectations when we recieve them. If we did, I fear Samsung mobile would be no more and it would be a toss up between Apple and Chinese companies with very suspect links to their Government.