I've also had an issue with a booking to Vancouver at the end of May 2022. Outbound seems to now show as being operated by a 777 (inbound changed to A380), but seat map showing on MMB is weird. Rows 2,5,6 & 7 showing. I was originally in 1K (row 1 no longer showing), but ended up in 2F. Not sure if it's worth calling in to get moved back to 1K, or if MMB will fix itself soon. Expert Flyer shows a normal seatmap.
