Describe the bug
Transparency slider doesn't work for tabs; it either ignores it or has 0% transparency when at any transparency setting except for 100%.

Screenshots

Distribution (please complete the following information):

• Archlinux

Color scheme in use (please complete the following information):

• Willow Dark Blur, Breeze Dark

Using Wayland (please complete the following information):

• Y

Using fractional scaling (please complete the following information):

• 125%, 100%

Darkly Information (please complete the following information):

• Version: 0.5.25-1

Plasma Information (please complete the following information):

• Version: 6.5.2-1

QT Information (please complete the following information):

• Version: 6.10.0-3

Additional context
This has been a problem across many color schemes for a while, since the feature was added. I can provide more screenshots or info if necessary.