@Joseph-TP Thank you for your answer, I have tested my own provider modem and there is a normal upload of 8 GB, but I use my own FS XGS-ONU-25-20NI, there I get down 8 GB, up 2 GB, from research it appears that the router does not support SFP + Flow Control, the upload problem remains. If a router supports SFP + then it should have its function.

  @Pro-gamer @Joseph-TP 

could your low upload speed has something to do with the problem discussed in this: https://community.tp-link.com/en/home/forum/topic/851396?sortDir=DESC&page=1 thread?

  @Bluefish91 As I said before, many people don't know, but if you do thorough research, you'll find out about Flow Control. If this isn't supported, you won't get an upload higher than 1GB or 2GB.

  @Joseph-TP no I mean when I use a provider's modem I get 8GB download and 8GB upload but when I use my TP-Link Archer GE800 with my own FS XGS-ONU-25-20NI I get 8GB download but upload gets stuck at 1GB 2GB because the GE800 router does not support flow control other routers like niFi Flow Control (IEEE 802.3x) is a network setting designed to prevent packet loss by allowing slower devices to pause data transmission from faster, upstream devices (e.g., 10Gbps to 1Gbps). It is generally recommended for mixed-speed environments to improve stability, though it may introduce latency in time-sensitive applications like gaming.

 Ubiquiti +4

 Key Considerations for UniFi Flow Control:

 When to Use: Enable if you experience packet loss, bufferbloat, or poor throughput caused by speed mismatches (e.g., 2.5Gbps switch linked to 1Gbps).

  @Joseph-TP The thing is, the Archer GE800 does indeed have a notorious software limitation: the option for Flow Control (802.3x) is missing from many firmware versions of this particular model, while it is essential to achieve the full 8Gbps upload speeds on the 10G ports. Without Flow Control, "packet loss" occurs when the router receives data faster than it can process it, keeping your speeds stuck around 2Gbps.