Forerunner 55 Update 11.02 accelerometer issue

FR55 firmware was updated but issue persists. One of the users provided me raw accelerometer signal:

the signal is recorded (captured by my app and saved in fit file) however it looks artificial. User did couple of swings of his hand in the air and saved activity but when reviewing the singal (picture attached above) it looks like couple series of repetable signal with EXACT same acceleration values being registered over and over again with exact interval. the signal is sampled 25/sec frequency and repeats at exactly same rate. 

Please advice the root cause of that issue. Similiar behavior was reported to me by other users of FR55 so I guess it is not malfunction of single watch device.

For comparison here is how accelerometer signal looks like while working properly:

(user hand swings are clearly recorded and visible - without any repetitive patterns)

Hi, I developed a Canoeing app ( https://apps.garmin.com/en-US/apps/23e5e52a-9a22-4120-bd63-39ba9b3cba3c ) that has exactly the same issue with the accelerometer only on the Garmin Forerunner 55. Many users complain that my app doesn't work on the Forerunner 55; some say it usually works but has now stopped, while others say it works perfectly fine on their Forerunner 55. This has been happening for quite some time. I don't own this watch, so I cannot analyze what is happening. In the Garmin Connect simulator, it works fine, but it doesn't in real life.

For me it looks like after one of the recent FW updates the accelerometer signal is not coming from sensor but from some dummy dataset as if it was broadcasting the simulator signal instead. Hope Garmin will follow up on it soon as a lot of people are reporting me this issue on Fr55.

I  have recieved  another report  of that issue for SquashAI app I released. I would appreciate if Garmin dev team could prioritize.

I'm keep recieving reports from new users that this issue persists..

Another test was done (by @flocsy) using FR55 (FW11.03) and FR965 by recording 30sec activities - he was trying to perform similiar hand movements for both recordings.

FR965:

FR55:

Raw data demonstrates similiar behavior to reported earlier:

Every 25 samples (1 second) the signal repeats but changes every 100 samples (4sec). FR55 signal, which was recorded using similiar hand movements, demonstrates some similarities so it is not 100% fake - for FR965 you can clearily see 4 hand strokes at second half of recording and for FR55 you can also see that 4 high signal patterns show up. @flocsy suggestion was that the the sensor records data for about a second, and then it sends the same buffer 4 times. Like it needs 3 seconds to reset the sensor because of some buffer overflow issue.

Bug is also reported here: forums.garmin.com/.../bad-accelerometer-data-captured-by-fr55-after-latest-update