I am referring to the glitch that has been leaving channels without spawn all the time. The glitch is caused by other people. For example, Person 1 could have no issues when killing on their own channel, but if they come to a channel with Person 2, the glitch will occur. Even then Persons 1 and 2 can both cc back to a solo channel and kill with no glitch. Other than this, there seems to be much inconsistency in replication. It is unclear why certain mobs will respawn but other do not. Sometimes the mobs that Person 2 kills will not respawn when Person 1 kills afterwards (but would respawn if Person 2 only attacks it). But other times random mobs in map that have been untouched by Person 2 will not respawn when Person 1 kills. In this testing, Person 2 had the NL quest "The One Hidden in the Shadow" active. After forfeiting this and relogging, it seemed to stop glitching. However, on another char who also only had that quest active, glitching did not occur. Persons 1 and 2 were not in the same party at all during this test. It is also worth mentioning that this is not the same issue as the no-drop one. They are probably related, but not identical.
It should be the exact same issue as the no-drop one. The player you were partied with was bugged and needed to forfeit quests. And mobs that either of you would kill would not respawn or drop items as far as I know. If you were not in a party then you would have been fine, and he would have just been bugged.