I called my insurance company and asked them to email me stating my name and that I was covered for x amount specifically for Covid and sent the email. I had originally sent the insurance certificate and the policy but I think it was too much info for the embassy staff to trawl through to find the info. A short simple direct email did the trick.
I had a return to my point of departure (portugal) but it was 3 months - she insisted we change our flight to return in a month! Thankfully I politely stood my ground as I was aware of the rules.
if they are in a position to stop you getting on a plane they need to be up to date! I was very unimpressed with the power and lack of knowledge this woman had!
We recently (2 days ago) had problems at Schiphol airport as our return was 3 months and the woman on check in stated we could only have a months visa exemption! I explained the Thai embassy knew our flight details for CoE and never flagged. It took time and her colleagues messaging another colleague for them to agree that any overstay was our issue!! Had to bite my tongue to stay polite - but they were trying to get us to change date on our return flight before letting us board!