Based on my knowledge, there are many factors that can cause Teams client running slowly, so it recommends you check these steps to see if it works in your environment.
1)Open too many applications at the same time. Please close the applications you don't need in your device and try to perform a clean boot in Windows check if there are the same results.
2)Network issue. Please check if you have enough network bandwidth and change another network connections. For more information about troubleshooting the team's low-bandwidth solution, you can refer to this article.
3)Teams client issue. Please make sure you have the latest version of Teams client and try to clear Teams client cache file, restart Teams client.
Also, check whether sharing is enabled in the Teams admin center. For more details about content sharing, you could refer to: Meeting policy settings - Content sharing
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.