Since the release of Windows 11 in 2021 you could no longer insert pictures into OLE fields of Access. In forum discussions this was mostly seen as a bug in Access. However, the problem lay elsewhere and also affected other Office applications like Excel and Word: With Windows 11, Microsoft had made changes to Paint, the OLE server responsible. The mspaint.exe became an MSIX app and Office could therefore no longer use it for pasting.
In a (no longer available) TechCommunity discussion a workaround was found which was the only remedy for more than a year and circulated accordingly. It consisted of changing some registry keys so that Paint became a working OLE server again. (see e.g. this discussion with according reg file download)
The Access team has informed us now that this OLE image problem was fixed with the big February update of Windows 11. Inserting pictures into OLE fields should now work again as in the decades before.