I need a book to write down my cords and its glitched

After i write something on a sign it just disappears afterwards, it stays there for some minutes and when i come back it disappears and the sign is blank and no one can see it, and with book with quills, i write something down, its stays for some time and suddenly disappears after i open it again, erasing the whole page also dont work, the text stays and can also come back, and disappear again. Also i tried to name my shovel with an anvil and also didnt work.
Im on my minecraft realm.