Timeline bogs down halfway through

Hello, I am new to the community and a pretty basic user.  I am cutting footage on a roughly 20 min clip and about halfway through, it starts getting really choppy and slow resposively.  The video will continue playing for another second after pushing space to stop.  Overall very poor response.  The only solution I have come up with is create a new project after each import as it gets painfully slow. 

I'm using a M1 Pro 16 inch.  I have cleared the cache and rebooted to no avail.  Nothing works except stopping and restarting on new projects.  This did not happen on my old macbook pro.  ( 2015 ) 

Anyone having similar issues or have any tips?  Thanks in advance.