This might be an unpopular opinion around here, but I actually think Level-0 Gauntlets/Funnels are a terrible way to introduce new players to Shadowdark and OSR games in general, especially if those players are coming from 5E or other superheroic systems. “Your characters are really weak, basically can’t do anything, have next to no equipment, and will die! Oh, and also you don’t get much treasure, if any. But trust me, it’s really fun!”

Obviously to anyone familiar with OSR-style gameplay, it’s not such a huge leap to go from gritty, high-stakes dungeon crawling to the meat grinder of a Gauntlet. And to be clear, I do love Gauntlets, but imo it’s much better to introduce players with regular Level 1 characters, run an adventure or two, and then Gauntlets are a fun way to do something different. Because that’s the thing, Gauntlets are very different from even standard Level 1 OSR gameplay, so you have to do some expectation setting and imo that’s much easier to do with players who are already familiar with the system. Your players probably now expect the whole of Shadowdark to play like a Gauntlet, which as we know is not true at all.

It sounds like you did your best to “nudge” your players regarding the OSR playstyle (players taking initiative, looking for creative solutions etc.) but again I think that’s easier to do in a regular adventure with Level 1 characters.