Why is my audacity slow

this has been going on for a while let me explain so I usually use tempo a lot when making my videos and recently every time I want to change the tempo it takes hours to finish loading to the range I wanted it in and recently I tried everything with downloading again and with trying to see if it was my wifi it cant be my wifi I recently got it fixed and I had people waiting for me to actually post and do their requests and its piling please help have to do my work. Thank you.

Do mean: “I usually use the Change Tempo effect a lot”?

Do you mean that the “Change Tempo” effect takes a long time to process the selected audio?

If so:
How long is the selected audio?
Is the “Use high quality stretching (slow)” option enabled?