Varying Speed in Original Media

I have used Audacity to successfully transfer audio from records to go along with filmstrips in the past. I have some Cassette tapes and on a recent tape I transferred toward the end of the 30 minute talk that goes along with the slides the narration starts to go very slow, but it’s a bit intermittent slow. I initially thought maybe the tape was sticking because it hasn’t been played in a while, but I recorded it a second time and had the same end result. Is there anyway to have Audacity analyze or autocorrect this to a normal speed? I’m open to any suggestions. Thanks

Audacity can’t autocorrect that.
There’s an app that can, called “Capstan” by a company called “Celemony”, but it is extremely expensive (list price: €3790, or €199 for 5 day rental).

You may be able to make some improvement manually using the “Sliding Stretch” effect, but it will be very difficult and time consuming to achieve satisfactory results:
https://manual.audacityteam.org/man/sliding_stretch.html

There’s also “Time Track” as an option, but in my experience that would be even more difficult:
https://manual.audacityteam.org/man/time_tracks.html