CssSyntaxError: Unclosed bracket

[merndev-agile]

To reproduce:
The stylus compiler produces wrong css for the kind of css written below that has a combination of multiple, multi-argument :not selectors.
This is reproducible on the stylus playground https://stylus-lang.com/try.html with the following code

.foo:not(.a, .b),
.bar:not(.a, .b) {
	color: red;
}

Current behavior:
The generated output is as follows: The closing bracket ) for the second :not is missing.

.foo:not(.a,
.b),
.bar:not(.a {
  color: #f00;
}

Expected behavior:
The closing bracket ) for the second :not is missing. Expected output should be like below

.foo:not(.a,.b),
.bar:not(.a ,.b){
  color: #f00;
}

Environment information:

stylus version: 0.59.0
nodejs version: 16.16.0