Ditto, for me the distinction was/is
Lizardmen: Humanoid body, although scaled/tailed/clawed, with lizardy head
Troglodyte: Blasphemous lizard that walks upright and uses tools
The other rmain distinction:
Lizardmen are like pulp savages (but more "cold-blooded"), they may try to cook and eat you or you might hire them as guides. Neighboring humans know about them, may know some lizardtongue, and some lizardmen speak pidgin versions of human tongues. Most lizardmen are neutral swamp dwellers, but there have been a couple lizardman adventurers, gladiators, mercenaries, etc. A lizardmen could become lawful good, a wizrad, a monk, what have-you.
With Troglodytes, nobody (aiside from eldrich horrors and sages who study obscure races) knows their language (which also uses scent, posture and color-changing skin to communicate). Trogs don't ordinarily communicate with other races, they just kill them, take their stuff, eat the bodies and sometimes take live captives to sacrifice. Trogs are ALWAYS chatic evil...they serve as a servitor/puppet race for demonic horrors (Demogorgon, Tsathoggua, Laogzed, Jubilex, etc). Trogs don't leave their nests and see the outside world, they don't have families, they don't drink alcohol or gamble, they don't really have possessions, they have a sort of chaotic evil "hive mind."