Synonyms of stumble upon in English:

stumble upon

(also stumble across, stumble on)

See UK English definition of stumble

phrase

1‘I felt like I had stumbled upon a secret truth’

SYNONYMS
come across, come upon, chance on, happen on, light on, hit on, come up with
discover, encounter, find, unearth, uncover, locate, bring to light
informal dig up, put one's finger on