Dear Experts,
We are testing a new LTE network, I notice only Samsung phones cannot upload, it downloads normal.
All other phone types was ok: download and upload.
Any clue?
What have you found in UE logs?
Try with other app as well.
Is this specific handset you have or all handset or same build and model have this issue?
All Samsung phones.
Only Samsung phones, all the staff who use Samsung get the same issue.
Record an UE log and share it here.
We can all have a look and let you know what is wrong.
Try also with nperf
See if it works with that one
Not just with speedtest but also with nperf.
I would say it is impossible not to work and is more likely a test method issue.
Yes, without proper UL, DL throughput can’t be so good.
Ok, do an attach dettach (airplane mode) and try again.
If still nok, please share a UE log.
I tried before it is same, will make log and share. 
One note, I make wifi hotspot from Samsung phone to share connection and connect to it using other Samsung phone it uploads!
Check your APN on phone and your AMBR for UL and DL.