Very slow read/write speeds & I/O errors on expansion storage

Sometimes I notice slow read speeds when trying to open the drive in a file explorer. Causes explorer to not respond. I would have to unplug and reconnect it to try to get it working. I use applications like Dropbox and P2P with it and would occasionally get I/O errors. My Dropbox wont sync new files on it unless I pause and resume syncing. It’s extremely annoying has anyone experienced similar issues?

What size expansion card do you have?

What OS are you running?

Is it overheating?

256GB

Windows 11

I’m not sure.
Here it is on idle.

When copying from the drive, the read speed was still slow

Here it is after 25 minutes:

Your drive is acting like it’s throttling and it is getting hot, although not too hot.

Some people have seen performance improvements by using a thermal pad to use the aluminum expansion card case as a heatsink.

I’ve done this, it’s very easy and requires $5 in parts (the thermal pad).

It certainly can’t hurt.

I have the same issue with the 256GB card. Looks like on sustained writes it overheats and then throttles from 400mbps down to 19mbps.
I tried to apply a thermal pad as described for the 1TB card ( 1TB Expansion Card Throttling - Framework Guides )

Still have the same issue with the card overheating and then throttling down. When the card hits about 63-64 C it will start to drop.

Still waiting for an answer back from support.