i don't use any pens or anything; just my finger on my samsung tablet (A7), how do i stop the app from deleting what i write when i put two fingers on the canvas?

[Potatsdrew]

i think the title is self explanatory, i've been trying the saber app for two days; i was intrigued at how i can sync my notes across devices, so i decided to give it a shot, here's the thing: it works great on my PC--flawlessly in fact! but the real issue is when i tried it on my samsung tablet; the writing is immaculate for someone who doesn't use a pen, but the problem is whenever i try to zoom in/out it automatically activates the eraser and deletes the line i just put down. I reaaaally wanna use this app, but it just isn't gonna cut it with this bug, i did notice that this has been a reported issue since November of last year, so i want to know if there's been any fix or work-around since then; because i couldn't find anything.