problems with typed arrays

[KOLANICH]

I have written a script.... But it doesn't work.
The error occurs in the middle of the library. I started to hack into.
And I have found that some variable which has the type Uint8Array when placed into instanceof Uint8Array gives false.
I was unable to reproduce it in a testcase (in a testcase everything works as it should work) so i'll give you a link to the original.
https://github.com/KOLANICH/ai-challenge-Exporter/blob/master/ai-challenge_exporter.user.js