Yes, Covid affected me too (I was stuck in the UK for 2 years). so did you just write to the pension service or is there a form to fill in - and something else if you advise the pension service surely HMRC will know you are not resident since every year when I do my return the system already has my pension in it (and if no direct communication some eagle eyed official could see that the amount doesn't increase).
However, thank you very much for your post very useful - as Tesco says "every little helps"