Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.67
Broken: version: 2.83.2, branch: master, commit date: 2020-07-09 05:50, hash: rB239fbf7d936f
Worked: (newest version of Blender that worked as expected)
Short description of error
Sometimes bone constraints just disappear after pressing CTRL+Z. This has happened to me multiple times but unfortunately, I can't reliably reproduce the issue.
Exact steps for others to reproduce the error
Unfortunately, I can't reliably reproduce the issue. It seems to happen often when I symmetrize bones with constraints, then decide to undo the symmetrization for some reason. The constraint that disappear can be set up many steps before the Symmetrize operation.