Crafting framed blocks on the architects cutter despawns the crafted items and its ingredietns.
Using v1.0.220-snapshot with Minecolonies (latest release) and a few other mods (like create, LEnders Cataclysm and stellarity) on my 1.21.1 neoforge server.
Class ArchitectsCutterContainer tries to call clear(), or sort() on ImmutableCollections which results in UnsupportedOperationException (supposedly).

Here is a part of the server log, when the issue occured:
Server log.txt

UPDATE: I tried updating mods to the latest versions, but that did not seem to fix the issue. What I found on the other hand is, that I can bypass this issue sometimes, by rapidly switching out the recipe for a different one and back on the architects cutter. Then I am allowed to craft the item, but this only seems to aply to one ingredient recipes (for example the panels).

Found the solution: I had the item banning mod installed, which according to what I found out, is known for causing such issues.