Audacity Custom Theme not working(Version 3.1.0)

[AzathothWAR]

After updating Audacity to the latest version 28/10/2021 , 3.1.0.
Custom theme has stopped working , tried to reinstall and redoing but still no luck.
I tried the "Audcaity Clean Dark Theme" from : https://forum.audacityteam.org/viewtopic.php?t=97814
as well as from a tutorial video on youtube : https://www.youtube.com/watch?v=mE0qkHSxgMM
Theme link : https://forum.audacityteam.org/viewtopic.php?t=100222&__cf_chl_jschl_tk__=d3ca8372eaa5660055577df8732672e3d935cf9e-1591467249-0-AQndHCEcrmrUHt5tmiPYvIw3ZJJpIUVUaXta-qPSVzYLd3R4T2NAN6P4GLvkDEyUY4uJ_rHLy0h3DNMGvvXWTIaJFQsEVCOZ2H5rsJLBpTJZgZWE1-TEExIsUSliRjO-MoGoEFCqUcDJZ3wRay1fMWvVR6JmzeEWm8vhQVK4kvW8g67qf4qxQjp9sLXAJPgLXYG7CBH_e-UB-N-fRa2-R0c8mJvfz9ZTV0L2WaZYIYCGnRNoppZSa5yqecR3iogTArIBYEEsE2RFtdPLzuTdGWDJ0bxeAx4jlWTkt7tiEVGT9lgZlhjcaiGTvvEQbC_MfdhPLLIwawffy0-XiGRk7hfiRS30kH1vIaLDizVJseK-

I've made sure to follow the steps accordingly to make sure I have not made any mistakes in installing the custom theme..

Below are screenshots as to what it looks like while "custom theme" is selected.

NOTE
Only Custom themes aren't working , the other ones such as 'Classic' , 'Light' , 'Dark' , 'High Contrast' has NO issue.

And here is a screenshot of whats in my theme folder

[LWinterberg]

(possibly vaguely related: #1487)