Will my prolonged absences due to Covid affect my EUSS application?

If Covid has caused you to spend more than 6 months outside the UK in a single 12 month period, this may not break your continuous qualifying period. You are permitted 1 absence of over 6 months but not exceeding 12 for an important reason, during the 5 years. You will need provide details of why you were prevented from returning, and dates.

If you have more than one such absence, or the single absence is over 12 months, this will break the 5 year period, and your 5-year qualifying period will likely reset once you returned to the UK.