That would be produced by the FAT32 IFS and shouldn't happen on an install, and perhaps you should open an issue as it is likely a problem at Arca Noae.
Once the install is finished, try upgrading the FAT32 driver, first with the one on the ISO to see if the error is repeated.
I think there is a newer one available at your subscription page, I have
W:\OS2>bldlevel fat32.ifs
Build Level Display Facility Version 6.12.675 Sep 25 2001
(C) Copyright IBM Corporation 1993-2001
Signature: @#Arca Noae:5.0.5.r240#@##1## 17 Sep 2023 14:16:27 ZOBOPEEP ::::0::@@FAT32 Installable File System (c) 2018-2021 Arca Noae LLC
Vendor: Arca Noae
Revision: 5.00.5.r240
Date/Time: 17 Sep 2023 14:16:27
Build Machine: ZOBOPEEP
File Version: 5.0
Description: FAT32 Installable File System (c) 2018-2021 Arca Noae LLC
Check the bldlevel of yours before updating