Steps to replicate the issue (include links if applicable):

• API calls:
  • https://crh.wikipedia.org/w/rest.php/v1/page/Suniy_zek%C3%A2/html
  • https://en.wikipedia.org/w/rest.php/v1/page/Timeline_of_the_COVID-19_pandemic_in_Canada/html
  • https://sr.wikipedia.org/w/rest.php/v1/page/Nau%C4%8Dno-stru%C4%8Dno_dru%C5%A1tvo_za_upravljanje_rizicima_u_vanrednim_situacijama/html

What happens?:

• 500 Internal Server Error

What should have happened instead?:
Page html returned.

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):
Based on slack discussion, this is a parsoid OOM issue.