Sort of off topic, but they are a BAEC partner.

Over the last few months very few of my Heathrow Rewards transactions have posted automatically. Doesn't seem to matter whether it's my physical card, the barcode on my phone or they enter the number manually the transactions very rarely post.

The only place I've had 100% success is World Duty Free (not that I buy much from them) but I've not had the same amount of success in M&S in arrivals (both T3 and T5 rarely works), WH Smith (sometimes works, but nowhere near 100%), the Geronimo owned pubs (Three Bells T3 and Five Tuns T5) never posted automatically, Dixons Travel mostly works.

Have others experienced similar?

I'm wondering whether it's staff training, poor equipment or just bad luck?

Heathrow Rewards customer relations are very good at crediting the points if you send them proof of purchase (such as a scan of the receipts), but I'd rather think of the scheme as one where I could hand my card over and then forget about it until I've earned enough points to move over to BA (or whatever reward I want).