Here are a few posts, with screenshots and details, posted on this forum. There are more users posting similar info, just need to digg them out searching. Some are long term bambu users, some are newer. Personally, I can’t pass judgment on all of them of being paranoid, or going over the hill, based on what they say and show, but I tend to concur with the observations made by several of them.
That being said, and before posting a few reference links for you to check out, do remember that the best (and most irrefutable) proof comes only from your own machine. That means that you need to check on your machine if indeed is calling home and/or sending out unauthorised data packages when in developer mode.
And now the links :