split unit dripping

I have a split A/C unit that runs fine for a bit but then starts dripping. I had a company come out and they poured water into the unit behind the filter and the water drained just fine so they declared it wasn’t a problem with the drain and the unit probably just needed a cleaning.

I did clean the unit but the problem persists. I have a few other of the same units and the tape/insulation around the drainage pipe (the part that hooks into the unit, leading from the unit into the wall) on this one isn’t as thorough. Meaning that the tape/insulation on the others covers the whole drainage pipe into the wall and this one doesn’t. Could that be the issue? The dripping drips from the lowest point of the drainage pipe though I can’t actually tell if it starts higher up.