Alt+up/down doesn't initially move FX in instrument effect chain

### System Information

Windows 11

### LMMS Version(s)

Version 1.3.0-alpha.1.842+2747b40 (unknown platform/unknown processor, Qt 5.15.6, GCC 13-win32).

### Most Recent Working Version

_No response_

### Bug Summary

When loading a preset into song editor from the sidebar that has multiple effects (eg: TripleOscillator Erazzor) and going to the FX tab, you cannot move the effects up and down by clicking them and using alt+up/down.
But if you switch to _any other subwindow_ WHILE that instrument window's FX tab is open, and then select the FX you want to move in the instrument window to reorder the effect up and down with alt+up/down, then it works hereon.

### Expected Behaviour

When loading an instrument with an effect chain, alt+up/down should move the selected effect in the effect chain up and down.

### Steps To Reproduce

1. Drag into song editor the preset `Erazzor` under TripleOscillator from the sidebar
2. Open instrument window of Erazzor and switch to FX tab
3. Select an instrument by clicking it
4. Use Alt+up/down arrow to move it up or down

Notice that it doesn't move up or down in this instance (though it can still be dragged to reorder)

5. Switch to ANY other subwindow (Mixer, song editor, even another instrument window) WHILE the instrument window is still _visible_ and open
6. In the instrument subwindow whose FX tab is open, select an effect you want to move again. Do not click anything other than the effect, _do not click the subwindow header or you will have to select another subwindow again_. Only click the effect in the chain
7. Use Alt+up/down to move it up or down

It now moves up and down.

### Logs

### Screenshots / Minimum Reproducible Project

https://github.com/user-attachments/assets/26c7659c-9149-4b98-8431-56262a5b91f9

Note: between 0:09 and 0:13, the time where the screen was still was me using alt+up/down on the effects chain even though it didn't work.

### Please search the issue tracker for existing bug reports before submitting your own.

- [x] I have searched all existing issues and confirmed that this is not a duplicate.

Start by reproducing the issue from the sidebar preset TripleOscillator Erazzor, then inspect the instrument window's FX tab and its effect-chain selection and Alt+up/down handling. Done means the initially selected effect can be moved up or down with Alt+up/down without first switching to another subwindow, while drag reordering continues to work.

Written by the indexing model from the issue text.