Not sure about there not being issues crediting miles flown on other *A carriers.

MS are usually very quick to credit the miles but I'm still waiting for my two most recent LH segments to appear on my MS+ activity log (you have to wait a minimum of 2 weeks before attempting to claim missing miles and the return flight was only 12 dyas ago).

If I need to submit a retro-claim I'll try to update with how smoothly it went.