CudaText: folding: any change to folded block will mess up this line (graphic glitch?)

1. In this GIF I use tab key and ctrl+z keys to do changes to a line but it can be anything.

graphic glitches: a strange line appears. also line text changes from { ... } to content of the first line. to take away this glitch just click multiple times on + or - buttons

1. When I insert some character (type any text) on this line the same glitch appears but all lines (expect first) will be removed and + - buttons disappear too.