rune pages won't save

issue: 1: making a new rune page 2: finnaly made my rune page 3: clicking save 4: the rune won't save (couldn't save)

I have this issue a long time but i can't fix the problem, I tried almost everything. the only way to change my rune page is logging into my acount on a other device. its very annoying that i can't save them on my pc, I have to use my friends pc for this, and getting every time blamed for using the wrong runes in game pls help. :/