Geckos which are much heavier can walk upside down on a ceiling.
When I lived in the Philippines, we use to catch them, and they could be up to a 6-12 inches long with an outsized head as wide as a shot glass, so...pretty heavy.
I had a broom, and swiped at one to knock it down to catch it, and it fell alright...right onto my upturned face.
As I shrieked and frantically swiveled my head from side to side in panic, I knocked my glasses off.
They came to rest about five feet away with the gecko firmly holding onto them still!
When I was living in Oz I saw one at least that big upside down on the ceiling. Huntsman spiders are fantastic climbers. In Australia you need to be constantly aware where you place your feet then along comes a Huntsman and you don’t know whether to look up or down.