Construction Unable to place Fuel Lines and Struts in Symmetry Mode after deleting one of them and press Undo

[Washed and Rusty]

Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows | CPU: NVIDIA GeForce RTX 3070 | GPU: Intel(R) Core(TM) i7-10700K CPU @ 3.80GHz | RAM: 31.92GB

 

If the undo button is used in the VAB, fuel lines and struts sometimes cannot be connected in symmetry mode. Fuel lines and struts can be placed one at a time after this bug is triggered.  Leaving the VAB and returning removes this bug until the undo button is messed with again.

How to reproduce most of the time:

1.  Radially attach two decouplers to a FL-T800 methalox tank.

2. Radially attach two FL-T800 methalox tanks to those decouplers.

3. Connect the outer tanks to the inner one with fuel lines or struts in symmetry mode.

4. Play around with undo button for example: hit once, or twice, or delete previous fuel lines and undo, or place a new object and undo that. Bug sometimes occurs after one undo, sometimes it takes a few.

5. Fuel line/struts can no longer be connected between tanks in symmetry mode.

I've also ran into this bug using medium methalox tanks and hydrogen ones. 

 

Spicat Edit:

Exact steps to reproduce:

1. Place a command pod
2. Attach a fuel tank
3. Attach fuel tanks in symmetry
4. Attach struts from the fuel tanks in symmetry to the center tank (struts in symmetry)
5. Select one strut and delete it (with the DEL key, deleting with the left UI is unreliable to reproduce this bug)
6. Undo
7. Try to place a strut in symmetry again

See the steps in this video:

 

Additional information:

Like you see in the video, even when you create a new workspace, you can't create struts anymore:

Workaround: Leave the VAB (like to the KSC) and go back to it

Edited December 30, 2023 by Spicat

[Spicat]

@Washed and Rusty, changed the title a bit and added more info (and a video) to show the problem.