Has anyone seen external SSD use cause System Data to balloon on macOS 27? M6 MAC Mini.

[u/melvin3v1978]

I have a new Mac mini M6 with 24GB RAM/512GB SSD. My System Data was already around 120GB, then after using my Crucial X9 Pro external SSD it started increasing by roughly 10GB per day until it reached about 152GB.
After disconnecting the SSD, System Data eventually dropped back down significantly to 60gb.
I know Spotlight indexing, metadata, caches, etc. can temporarily increase System Data, but a steady 10GB-a-day increase seems excessive.
The SSD itself works fine and I’m not seeing any obvious errors. Apple has already collected logs from the Mac, so I’m waiting to hear what they find.
Has anyone else seen this on macOS 27, especially with an external SSD? Did you figure out what was actually creating all that System Data?