I really love qBittorrent and that's what keeps me around

Could anyone of you guys help me find the solution? It must be a settings issue.
Here's my router setup. I haven't done anything manually since "UPnP IGd" seems to works just fine (qBittorrent creates its own port forwarding rule).

Here are some setting pages:




I've tried to do some troubleshooting on my own:
- Disabled uTP and only using TCP (a couple of posts stating that uTP might throttle speed)
- Disabled Local Peer Discovery (I'm not in a big LAN)
So to sum it up: Excellent Speed while downloading. Uploading reaches near my potential speed for a second or two, but then turns down to about 1/35 of my real capacity.
Desktop Setup:
AMD Ryzen 2600X
16GB Ram
2060 RTX
SSD 500GB + 2TB 3.5"
Wired to Router. Router Wired to FTTH.