Are you getting any prompts to calibrate obstical avoidance or vps when on, this can be done with dji assistant 2 on computer,,I turn mine off,,,,,,,just check that there no plastic protector covers still on the lens ,sounds dumb but been know to happen,,obstical avoidance useless in the air,only handy if around trees at low altitude
When you say you receive no "prompts" how do you know that the aircraft is constantly braking if the app does not tell you?
Have you taken a look at your flight logs to verify this? If not, upload your .txt device log to the link below and take a look. If you need assistance with that, post a link to the uploaded file back here. The link below is only for the .txt log. The mobile .dat will have much more information.