Clicking on the photo in the preview corresponding to (track 1) jumps to another one from (track 2)
Opening the photo in pip editor would be an answer, it turns out that the mask for track 2 doesn't show up so you can see how it's turning out.
I thought maybe I had to hold down a hotkey, but I couldn't find which one.
On the other hand, working with pip designer is extremely heavy, it took a long time for things to happen.
My PC is not a “Ferrari”, but neither is it a “bullock cart”.
I've been experimenting with other apps, even online, and things really flow quickly and smoothly. XEON-E5-2680 v4 / Mem. 16GB DDR4
M.2 NVME 512Gb / 2-SSD Sata3 1TB
AMD RX570 / Display Philips 272V8
Windows 11_64Pro / PD22/365