Stretched, warped photo scan with Epson FF-640?

[Closecall]

I have been experiencing an issue during some scanning with the ff-640 where the image seems to get stretched or warped. It seemed very random at time when scanning photos and have done tests to see if I could figure out the cause whether it being dirty rollers, dirty or sticky pictures, orientation, jams, nothing could make sense of it.
I then tried scanning the same issued image with the page separation button toggle up as if it was a thicker postcard or using the carrier sheet and the photo comes out perfect. I have experienced this may times and it doesn't make sense.
It also has slowed my progress with digitizing a bunch of family photos and hope someone can help me figure out if this is common or fixable because scanning photos one at a time is not fun haha. I can do them in batch still no problem but i have to be overly thorough to make sure there is no stretching or warping.
I have also testing this on a different ff-640 and same thing, Epson support has 0 clue as well.
Thanks all.

[lordsmurf]

That such a miserable scanner. I had one, returned it. It took me over a year to find a non-flatbed scanner that could give a good quality scan, without screwing something up (either visually, or by scratching the photo).

As of Dec 2024, I now have the most recent edition of the Ricoh ix100.
https://amzn.to/3FJtDDq

Yes, it's "one at a time", but I can whip through so many images, just handing feeding at my desk, one eye on the monitor, one of the scanner. In the longer term, screwing around with a document feeder wasted more time than hand feeding to a good scanner.

When quality matters, I still use our Epson V600, or Nikon V negative scanner. But for quick quality scans, this is hard to beat.

All document scanners get dust buildup on the CIS (thin CMOS), but I use a Giottos blower on it if/when I see issues. I also blow off each photo before inserting. Just a few puffs, few seconds. I'm just a gear in a cog on those weekend days. (I've not had any scan times lately, need to resume.)