Construction Parts breakdancing while using the translate tool when root part set to a part on symmetry

[Spicat]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 10 | CPU: Intel(R) Core(TM) i7-10700 CPU @ 2.90GHz | GPU: NVIDIA GeForce RTX 2070 | RAM: 16GB

 

Steps to reproduce:

1. Place a part
2. Attach parts on symmetry
3. Set the assembly anchor to one of those part on symmetry
4. Move one of the other part on symmetry with the translate tool

Video evidence:

 

Edited January 29 by Spicat

[EcoAlpha]

Same thing happen,at least to me, if you do this. E.g. : 

Place a tank
Put 3 small engines without snap but symmetry (3)
Change symmetry to, eg. (2)
Try to rotate engines

It's a similar situation.

[rogerawong]

Whatever the issue turns out to be, I bet it has to do with quaternions.