PSA : Take everything you read here with a grain of salt. I got SA after 17 months. During this time, IRCC did not ask for additional documents nor did sponsor's situation change from the time of application submission in ANY way. People kept saying there MUST be something wrong with the sponsor's situation and we kept stressing ourselves out over what could be the reason. One day when we were least expecting it, we got biometrics request followed by sponsor approval a week later. It seems as if it was just a COVID related delay.
Fair enough. I certaintly should have noted that 'something wrong' with the sponsor approval certainly can/could include a simple (or complicated) bureaucratic mess. But probably more chance there is something wrong.
If you can attempt to determine if there's anything at all through gcms notes or MP or however. If there really is nothing - or it's a mistake - hopefully you can shake it loose.