Multiple miscarriages, what tests to have

[Orizzy]

Hi, after reading these forums for years, this is my first post. I have recently had a missed miscarriage at 17 weeks, I was carrying MCDA twin girls. Previously I have had 2 chemical pregnancies last year that I tested positive and then negative after 2 days.
I had a failed round of IVF last year, 10 eggs collected, 5 fertilised, 1 achieved day 5 blastocyst but was not viable after PGTA testing.
My latest pregnancy was a donor egg IVF cycle. We are currently awaiting the autopsy results for our daughters, hopefully within the next month.
I am 41 and my husband is 48.

I am looking into tests to see what could be the issue, I had a consultation with DR Gorgy in London who recommended various tests but I’m so unsure. I have had transvaginal scans with 6 different clinics during the last 18 months so feel if there was an issue with the uterus etc that would have been noticed?
All bloods done in clinics have been normal and I don’t have endometriosis, PCOS or anything else.
I was thinking of starting with testing antibodies, KIR Genotyping and PAIP tests before moving onto NK assay panel. I thought also to do the high vaginal swab for infections as well as semen culture and sensitivity. My husband has been tested before and no problem found with sperm and he already had a child.
I feel very overwhelmed with everything and totally lost, I’d love to hear any advice from anyone who’s been through it or could recommend?