Spider works locally, but not on scrapinghub

I'm running a very simple spider that sends two POST requests. (code attached) 

On my home computer it works just fine, but on scrapinghub I get the same error for each request sent:

``

[scrapy.core.scraper] Error downloading <POST https://baca.ii.uj.edu.pl/p12018/testerka_gwt/problems>: [<twisted.python.failure.Failure OpenSSL.SSL.Error: [('SSL routines', 'SSL23_GET_SERVER_HELLO', 'tlsv1 alert internal error')]>]

``

After that, the spider stops, there is no data collected.

I think it has to do with the site's certificate being outdated, but in the docs it says that Scrapy doesn't check that.

Any ideas?

Thanks