I can't say that your *.gif explains all that I suppose was thinking (gif is cut out, so complete viewing area is not presented)... I remember that when A2018 new features came, one of the first things was selecting on double monitors, or single one where you start selecting in one portion, then pan and continue, first viewing is off screen and you still in selection mode... When finished, it was gripped/highlighted all when zoomed out... I suppose the same thing is with stretching, just never tested, so that I could state - bug... Bug was with vla-add3dmesh - @Dominicomaria presented when attempted to create BOX... Bug is when I tested (vlax-curve-getpointatdist) providing distance greater then complete length of curve - ACAD throwed start point instead of nil... Bug is when you set QAFLAGS sys/env variable to 1 and ACAD start to behave strange with commands LAYER,..., so I always say reset it as soon as possible to 0... There is also ACAD 2015 VVC error, when using command functions inside (mapcar '(lambda ( x ) ...) lst), or using command instead command-s in error handler... And also memory problems when ACAD crashes - without any reason, or with something not explainable...