Your system information

• Steam client version (build number or date): 1690583737
• Distribution (e.g. Ubuntu): Fedora 38, Kernel 6.4.13
• Opted into Steam client beta?: [Yes/No] Yes
• Have you checked for system updates?: [Yes/No] Yes
• Steam Logs: logs.tar.gz
• GPU: AMD

Please describe your issue in as much detail as possible:

When download limits are turned off Steam uses 100% of my bandwidth 40MB/s. [Working]

When download speed limits are turned on the speed cap is limited to 20MB/s no matter what upper bound is given. [Broken]
25000KB (25MB) -> 20MB/s
40000KB (40MB) -> 20MB/s
4GB -> 20MB/s

Anything 20MB/s or below behaves correctly.
20MB -> 20MB/s
10MB -> 10MB/s

Troubleshooting:
Wiped all steam configuration.
Tried latest Beta.

Steps for reproducing this issue:

1. Disable download caps and check if you are using your full bandwidth.
2. Restart steam.
3. Set the cap manually to your max speed in step 1.
4. Increment down to slower speeds and observe the behavior.