My classes are all online.
Tech problems on presentation videos receive a 2-6 hour grace period as long as they notify me immediately and don't abuse my leniency, because even I have had problems uploading shit to our LMS.
Anyone can have a 24-48 hour extension on a paper, for any reason, if they request one 24 hours in advance. With extenuating circumstances, they can an extension of up to a week. If they need more time than that for reasons other than getting COVID, it has to go through the Dean of Students or Disability Office. If they get COVID, I tell them to focus on their health first, and we negotiate an extension on a case-by-case basis based on how they're doing.
Beyond that, it's 1/3 letter grade off for every 24 hours late, but the late penalty stops when they're down to a C. They can turn in work for a maximum grade of C (but it's still graded - they'd need to get an A to get a full C) as long as I have time to grade it before the end of the semester.
They have a 4-day window to take exams, so no late exams are accepted barring truly extraordinary, well-documented circumstances.