Hriston
Dungeon Master of Middle-earth (He/him)
This sounds like a communication problem with your DM. My first question in attempting to sort this all out is whether you are in combat, i.e. has the party or the monster taken any hostile action against the other? It's unclear to me from what's been said whether that's the case. To "stealth" can mean different things depending on whether combat is underway. It sounds to me as if you are attempting to move at a slow pace, relevant to exploration out of combat, whereas the DM is treating it as a situation where initiative has been rolled. This needs to be cleared up before a determination based on the rules can be made.