Technically you are right, but since this is Epic we are talking about here, try and doubleckick the node to read through the function and what it does - verify that what you assume is correct.
Also, instead of trying to figure stuff out you are probably better off starting from scratch in .25 or .27 or any engine version that actually works (so nothing makred as 5).
The engine is years if not decades away from being out of beta and reliable - and i think you are definitely experiencing some of that here.
On a thing thats always worked well before but which they just messed with to get Nanite running.
On that note, before you do make the migration (which can take loads of time), you can try to turn off all the newer stuff - related or not - which you are able to turn off. Like Nanite.
Short of that. Nothing much for your specific case.
One thing maybe.
Try and access the foliage, select invalid, and delete them.
Its possible that invalid elements are causing the issue - but your error log, if you know enough to monitor it, would have been screaming at you about stuff like that for months…