Text editor keeps changing input to start of first line for no apparent reason

[InsertUser]

Describe the bug
When typing a description for a node the input swill suddenly switch to the start of the first line in the window. This causes the editor to have a fit because it doesn't recognise the chart type. Needless to say this is incredibly annoying.

To Reproduce
Link to Live Editor: a link with nonsense in it (note that the text field starts with "jk" the next two nonsense characters I was typing on line 4)
Steps to reproduce the behavior:

1. Create a new flowchart
2. Start typing new nodes and descriptions.
3. At some point in typing out a chart the input will jump to the wrong place and text input will continue there.

I can't be more specific as it just seems to happen for no reason.

Expected behavior
I expect text input ton continue in the place I was typing half a second ago not in a completely new location.

Desktop (please complete the following information):

• OS: Window 11 Home
• Browsers:
  -- Firefox (version 130.0)
  -- Microsoft Edge (version 128.0.2739.79 (Official build) (64-bit))

Additional context
At first I thought this was related to the appearance an disappearance of errors for part completed connections with text |on the arrow| but I have since seen this on other occasions. It is bad enough that I think it is best to edit in a text editor and copy the text across when a line is complete.

[MgGriebZ]

I experience this constantly as well, any chance anyone found a RCA?

[sidharthv96]

Can you please share a screen recording?
I don't have access to a windows machine. Tested with Firefox, Chrome, Safari and Brave on macOS.

Screen.Recording.2025-04-24.at.11.15.06.AM.mov

[Mqlvin]

I am also having this problem, here is a recording of it. Unusually it happened twice or so in the 20 seconds I was recording - this is a bit more frequent than normal.

My cursor gets placed at the start of the editor so my text ends up there - the first time it happened I had stopped typing so I didn't add anything to the top of the box. The second time I finished my word at the top of the box.

2025-04-24.15-14-03.mov

I'm not sure at all of how the live editor works so I don't know if this is useful info, but there are no errors in the console, other than the UnknownDiagramError because I've edited what should've been classDiagram at the top to ructionclassDiagram.

[leandroluk]

Maybe the editor needs to be maintain the edition content in an runtime store (like zustand) and use a debounce function to update diagram and URL

[sidharthv96]

@Mqlvin, I was able to reproduce the error, but it's very random, so figuring out the root cause is gonna be tricky.
@leandroluk we're already using stores, and debouncing the URL writes.

[denny-futurice]

For what it's worth, I've found that this issue gets significantly worse the longer the diagram gets.

I often do not experience the issue, but once a diagram gets to more than 75 lines (maybe entities is a better measure) it starts to happen.

In addition I noticed that it seems that the move of the cursor happens the moment tab completion triggers.

[MgGriebZ]

For what it's worth, I've found that this issue gets significantly worse the longer the diagram gets.

I often do not experience the issue, but once a diagram gets to more than 75 lines (maybe entities is a better measure) it starts to happen.

In addition I noticed that it seems that the move of the cursor happens the moment tab completion triggers.

I still have it happen with short diagrams, but I think I agree it happens more as the diagram builds larger. I am not sure how to reproduce but what I have suspected is typing too fast somehow conflicts with the autocomplete options.

I am using Edge on work machine (azure virtual machine) and personal PC and experience the same issue in both cases.