The quality of the video call would also depend on the speed of both of your devices. What I could suggest is to try using the Teams web client to check if you would experience the same issue.
Also, you could try checking if you could adjust the bandwidth of your internet connection in order for the quality to improve.
https://learn.microsoft.com/en-us/microsoftteams/prepare-network#bandwidth-requirements
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.