Resolved Photos Library on EXTERNAL DRIVE Still Taking up Space on Local Mac Storage

[GV123]

I keep my default Photos library on an External Hard Drive (selected as default in preferences)

However, I recently transferred up about 20 gb of photos off my iPhone into that library, but it still took up 20gb of my internal storage too. Tried to locate where the photos may have been backed up or stored on my local drive, but I can't find anything in my internal SYSTEMS or LIBRARY folder that corresponds to the photo transfer.

FYI I have no other local Photo libraries, only the one on the External Drive.

Anyone experienced anything like this? Your help is greatly appreciated!

Catalina 10.15.7
iOS 15.1
Photos Version 5

 

[GV123]

SOLVED.

It was an iOS backup that took up the drive space.

Went to the ABOUT THIS MAC, and STORAGE, and saw iOS FILES was 300gb deep in iOS backups. Deleted and holy cow, got a bunch of space back!

FYI for future reference.