qBittorrent official forums

Qbittorent 4.1.5 Global Upload Speed Limit Overrides even if set to any values, if kept at 20 kiB/s after time it goes beyond the value. Must fix a value must not go beyond that as it affects download speed too. Rest fine.

qBitTorrent doesn't seem to precisely hold a value, but at least for me tries to stay in the ballpark.
Do you have qBitTorrent set up to allow local peers/seeds to override the global limits?