When it’s running through BigFix, it’s executing under the ‘LocalSystem’ account unless you override that. Lots of examples of overrides at Tip - Action Override User settings
It might also be helpful to save any command-line output to a file you can review later, in case there are some error messages. I posted a summary for that at Tip: Running Commands and Saving Output (Windows)
It could be that ‘winget’ requires a user session rather than LocalSystem, or that the particular package is installed per-user and only some users have it ‘installed’. Saving the command line output and posting that here may help.