The topic was started for a problem with Parallels 16. A newer version than the 15.1.5 you are suggesting to upgrade to. Therefore the original question remains unanswered/unresolved. I have had the same issue on all Parallels versions since the upgrade to 16.
I just upgraded to version 16.5.0 (49183) and the issue remains.
Extreme use of CPU during Teams meeting especially while sharing a screen. It drains a full battery in 30mins.
MacBook Pro (13-inch, 2019, Four Thunderbolt 3 ports)
2,8 GHz Quad-Core Intel Core i7
16 GB 2133 MHz LPDDR3
Intel Iris Plus Graphics 655 1536 MB