No loot filters on, loot going straight to stash instead of dropping. So far has happened in undercity runs, lair bosses, and pit. Very noticeable in undercity since the little notification exclamation point appeared on the stash in the boss chamber as soon as the boss died.
Everything that drops from the boss is picked up, right? Nothing visible on the ground like what would happen if a loot filter was on?
Some of the loot is visible. Other loot goes straight to stash. Happened to me and a friend together playing together, and to me on my own. No loot filter on at all. No portaling out (like with missed loot). Kill undercity boss (for instance) some loot drops, some loot goes immediately to stash. Logged out then logged back in and it still was doing it. Quit and restarted game and same thing.
Just as a test, try:
Export your current loot filters. Then delete them all and disable loot filters completely.
Kill the same monster/boss that you did before and see if the result is repeatable.
You’re describing what appears to be a loot filter, even though you said it is not turned on. So, we are eliminating a variable by removing the existing loot filter and disabling the feature.
The export is so that if you have loot filters set up the way you want them to work, you don’t lose them.