It's actually tricky to reproduce, as it doesn't happen every time, though there might be a way to get it consistently.
Blueprint string:
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
This blueprint consists of two mini compact processors, but in order to get the wanted effect, first place the lower processor, and then the upper one, the order in which they're placed matters. If they're placed in opposite order, I/O point names won't show at all when hovered with cursor. Also, make sure to place this blueprint far away from any other already existing processors, just in case. With this, I managed to reproduce the bug every time. Hope this helps.
