Abnormal sound of machine tool

This is my CNC machine tool. I use it for laser processing. For the XY axis, I use Kollmorgen drive and Kollmorgen linear motor. For linuxcnc, I use version 2.9 and ethercat communication. But it occasionally produces abnormal mechanical noises like the ones in the video. When I restart the software, there is a high probability that the abnormal noises will disappear. I found the result " forum.linuxcnc.org/ethercat/43855-delta-...ication-issue#222451 " in the forum, and I followed the explanation inside. I changed refClockSyncCycles="-1". I'm not sure if it works, but doing so often results in Estop in operation. So I had to set refClockSyncCycles="5", this is my initial configuration. At the same time, I also checked the following configuration and there is no problem
-0x60C2:01 = 0x01 (interpolation time period 1ms)
-0x60C2:02 = 0xFD (interpoltatin time index 253)

Who can help me solve the problem of abnormal noise? Thank you very much

Supposing it does not have belts, so do a hal scope of joint.N.motor-fb when that sound is present.
What type of feedback?
Does sound like encoder missing counts occasionally... so does the machine vibrate with those sounds ?

I use a linear motor without a timing belt. I think the machine tool moves smoothly when abnormal noise occurs. So I think there is a problem with the ethercat connection, because this situation will disappear when I restart the software, usually this situation occurs in the morning when the machine is turned on. The feedback uses an incremental encoder.
I use Google Translate, if there is a deviation in the translation, I am very sorry

I think you should find out the cause of the noise and then find a solution to the noise.

What should you do if the encoder occasionally loses counts? What should i do?

Have you checked the host PCs latency?
Thumps and bangs can be latency related...