10s BMS with 5 leads - Good or bad design?

Taking apart a failed 10s/ 36v battery from a Landwheel and this is BMS.

I build electric bikes and am family with BMS / PCM systems but I’ve never seen a BMS like this before. I should add that out of 6 batteries, 2 have failed. I’ve not had a chance to test the 2nd failure but the first indication on failure £1 was that they it charge. After poking around with a volt meter I found 3 x cells at ~1.2v. So my guess is that either the BMS is failing to cut off voltage or perhaps just the cells are low quality.

Has anyone seen anything like this before?

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