Automatic Underground belts break in specific arrangement

[Summoner99]

When dragging belts, there is a wonderful feature that automatically adds underground belts. Generally it works but in this specific arrangement, I notice it seems to not behave as expected

Its not letting me upload photos so I'm attaching them via a postimg link
https://postimg.cc/gallery/QCrkNPL
1. Before
2. After - what actually happens
3. After - what I expect should happen instead

I grab a red belt and drag left starting at the yellow belt

[Loewchen]

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