This problem has existed for more than 3 hears and I have found nobody, even after jumping through the trouble shooting tips has achieved a solution. Do we assume that GS and Apple have given up since there will soon be a parting of the ways?
iPhone 15 Pro Max, iOS 26
I have never seen an Apple Card transaction not showing in my Wallet whether I am using Apple Pay or manually using the card number. Are you maybe using a VPN?
Since it appears you have been having the trouble for 3 years, I see no connection to any change in management of the Apple Card being a potential cause.
Since you refer to GS, I assume you are talking only about the Apple Card. Apple Pay is not specific to GS. It is unclear since you posted in the Apple Pay forum and not the Apple Card forum and the transactions you see in the Wallet are provided by the bank of the issuing card.
Transactions not appearing in Apple Pay
