Difficult spec refuses to work with generators and some linters.

I've been trying to solve this for a month and IDK, I'm at a crossroads now. Nothing seems to like this spec but I really need to generate Python and PHP from it. I don't own the spec but the people who do assure me it's valid. Passing the spec through Spectral (the only tool that actually produces any useful output at all) shows over 2000 errors and warnings. I've tried Kiota, LibLab, Fern, OpenAPI Generator. There are weird things that happen with some generators, for instance time-of-day should always be a string but some methods are generating with integer as type.

I would really appreciate any recommendations or advice you might have.

Here is the spec if you want to take a look
https://cdn.veeam.com/content/dam/helpcenter/global/reference/vspc_rest_81.yaml