MacOS Sequoia and Synology NAS -- SMB protocol issues?

In early fall I started noticing strange behaviours with my Mac

- NAS mounted drives suddenly ejected when exporting, copying and deleting files

- could not copy or delete large numbers of files between NAS drives without errors stopping the processes or drives ejecting.

- lag in playback with Adobe PremierePro

- odd RAM previews and lag in Adobe After Effects

- DaVinci Resolve exports frequently failed and ejected the drives.

This was happening on MacPro Intel 2019 systems and our MacStudio M2 chip systems

We found many posts from other users wth NAS systems who reported the same issue

and either were frustrated like we were

or just copied media to their internal drives first and then back to the NAS.

(a whole lot more time and work)

I paid a Synology expert to go through all our Synology system settings and ensure everything was top-notch and try and identify where the issue could be.

He could find nothing.

I sent through rounds and rounds and rounds of discussions and trials and system logs and code with Synology, being escalated to the top developers.

Nothing could be found by their teams.

The only factor that we could not rule out was our office jumped to MacOS Sequoia sometime before the symptoms appeared.

Last night we tried updating to 15.2 to see if it would help.

It got SO much worse - causing a huge number of problems on our MacPro Intel 2019, OWC breakout boxes and external USB-C drives.

So our logic was, if we're going backward, let's go WAY back and restore from just before we upgraded.

So we backed up our internal drives for safety

created a Sonoma thumb drive installer

booted in Restore mode,

wiped the internal system drive,

reinstalled Sonoma and then restored our Time Machine backup from Sept 16th, 2024

After starting up and re-configuring and authorizing a bunch of system settings

We ran our usual tests.

And the copies and deletes we could not do? They got done. No errors at all.

First time in months this basic OS process did not fail.

More testing needs to be done but for now it appears we can't upgrade our systems to Sequoia until we're CERTAIN Apple has fixed this issue.

We hope it's soon.