I SOLVED IT ON MY IPHONE WITH THE FOLLOWING STEPS!! :)
After months trying to fix the voice memos app being to heavy issue, I came to a solution that helped me.
READ THROUGH ALL OF IT FIRST
Transferred all voice memos to computer for backup
Deleted the app
Turned off Voice Memos in iCloud storage settings
Re-installed the app making sure I didn’t enable iCloud on Voice Memos right away.
Went to Settings>Voice Memos>Clear Deleted>Immediately
Went to Voice Memos app and created a Voice Memo (this should be the only voice memo) and then deleted it immediately. After that, Voice Memos app was only a couple megabytes and then re activated iCloud.
You can try maybe just changing the setting in Voice Memo to Clear Deleted Immediately before deleting anything, then create a voice memo and dele it and see what happens. If nothing happens, then go for all of the steps. I hope this helps :)
PECOS