Since the sourcepawn (compiler) update from november (2021) or so, it seems like that Setup-SP will no longer work with latest SM1.11 versions.
Examples:
https://github.com/surftimer/Surftimer-Official/runs/4343458952
https://github.com/Bara/Multi-Colors/actions/runs/1511711441
While testing this in a VM with Ubuntu 20.04 and VSCode, I couldn't reproduce this.