Private Residence Relief on CGT for Crown Servants posted overseas

I would really appreciate some advice on Private Residence Relief for Crown Servants. I bought my home in 2015 and from September 2016 - 2020 I was posted overseas as a Crown Servant. We then returned to the Uk for 7 months and lived in the house before going overseas again in 2021. It has been rented most of that time. We are currently still overseas and will return next year. In May this year we put our house up for sale (no buyer yet) and hope to sell and move before we return to the UK. Can someone please advise if PRR applies for the whole period we've been overseas? If so when does it end? Is it the point we put the house up for sale, or the point we sell? Would if make any difference if we move back to the house before it is sold? Thanks very much.

Hi,
You can see guidance here:
HS283 Private Residence Relief (2024)
CG64555 - Private residence relief: two or more residences: job-related accommodation
Thank you.