Strokes is getting deleted while writing

When I’m writting with a stylus while keeping my hand on my iPad 6th gen ios 12.1.4, some of the strokes keeps dissapearing My attempt to resolve I found solution online suggesting me to turn off magnification feature . But this dint work the issue still persists. Also this issue happens with Apple Pencil,and many users have complained about this I tied reaching Apple care people they were of no help. So how do I resolve this issue?