So, I found the issue, but not the solution. When the test fails, -M $file is a negative value like -1.15740740740741e-05.
I can reproduce on a local machine, yes. It happens maybe 10% of the time, which is weird. I had tried adding a delay already. I just tried increasing the delay to a full 2 seconds and that didn't help.
When the test fails, I do see the file pop up momentarily in the directory. So it definitely exists (and the previous test proves it).
$PM = "Perl Monk's";
$MCF = "Most Clueless
Friar Abbot Bishop Pontiff Deacon Curate Priest Vicar";
$nysus = $PM . ' ' . $MCF;
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