this is completely intentional. You can probably tell that the PSTN does not treat the FRME as an object, and making it do that would take a bit of work. Also break a bunch of things and change PSTN from the way people expect it to work.

It only sees the line of FRME right in front of the last PSTN, so in one there is a missing part in the line, so it only pulls up to there. In the other the FRME is blocking it from retracting so that's what's causing the problem there. There is nothing to fix.