Anova sealer pro accessory hose vacuuming

Hello All
I just got a Pro Sealer which I am happy with. But had some issues with the accessory hose not sealing jars but as I read here you have to really push the end into the sealer ( even though worried I may be damaging the device). But I have noticed the hose cycle cannot be stopped manually as you can with sealing bags. I just have to wait for the cycle to finish and pressing the hose action button does nothing. Is this supposed to be this way or should you be able to stop it.
Thanks for all your help.

Just noticed the port is labelled external pulse , so presumably it should start and stop like the other pulse button. But if you have any thought I would appreciate hearing from you.
ps have asked Anova support but they have been taking a while to answer.