Hello "Loco loco" (Please sign your posts, it makes it a little more friendly)
The one small piece of information you have not provided is, have you upgraded the "crippled" chip in the decoder ? The original OEM chips in the first series of Atlas and BLI locos were victims of the Mike's Train House fake lawsuit where he falsely claimed to have invented features used in the decoders. He naturally lost the suit but only after forcing years of legal battles. During those years, QSI was forced to disable certain features of the decoders like BEMF, speed tables and more I can't remember. Since manufacturers had already started production on those locos, QSI placed "temporary" and removable chips in the decoders. The plan was to provide free upgrades to owners after the suit was settled. Unfortunately, Mike used years of legal tricks and false info to delay the inevitable and "free" was eaten up by legal fees.
When Mike finally was beaten, QSI came up with both the upgrade chips and a programmer that would make the upgrade a universal chip capable of having any sound file loaded into it or having the chip pre-programmed with specific sound files. Most problems with the Atlas and early BLI locos can be solved with the new chip. The original chips have a LOT of quirks and failures hanks to Mike. The chips are still available from different vendors and I think one is Litchfield Station. Tony's is another. They usually run about $30.00. Quite a bit cheaper than "removing the decoder" with another brand.
The suggestion on replacing the wheels is a possibility but after almost 25+ years of operation on both home and club layouts, I have not had to do that on any of mine yet. One small exception was the case where two of three consisted locos "de-consisted" at an op session and the operator only mentioned how bad they pulled his 15 car train. Naturally, they were both six-axle units and all wheels were flat-spotted after the one loco dragged them over the entire layout. Lesson learned, do NOT have consists coupled before the session.