The text almost always immediately disappears after the sign is placed. But, when it sticks it will work normally for a while for additional signs and renamings.
In my case, I am on PC, the anvil takes damage from each attempt, but does not consume my levels. Yet, persistently cycles back to the input slot. It does, however, take the levels of my friend, who is playing on XBOX.
In addition, all of us are having issues with text on signs. We have found that if the text sticks, then anvils will work for renaming. However, when it comes to my friend on XBOX, even when the renaming succeeds, when he relogs the item will apparently lose the new name.
This is a follow up to my previous comment.
We loaded a backup from before this issue occured and destroyed both ends of the netherword portal leading to and from the Gold farm near the large village. Since then, this particular issue has not yet reoccurrd.
I logged out at our gold farm (which was off) near a large village. Afterwards, whenever I tried to log onto the realm, it would load to the point where it says it is "generating the world" and then either disconnects immediately or disconnects the second my avatar is visible.
I downloaded the realm and tried it on SP. It does not disconnect, but it might periodically crash the game while playing. I loaded a backup into a second world, from before the disconnects happened, and it worked fine. But, testing showed that the village/gold farm has a high chance of recreating the issue.
So far, no one else in our realm is affected. One person logged in to check the realm and it seems, aside from what I am experiencing, it is perfectly fine.
Edit:
The basement of the gold farm, where this issue seems to trigger, has a portal to the nether.
Edit 2:
Prior to this, when the XP glitch was reintroduced, our players had issues with signs and nametags. The text on signs would often disappear after being written and when this occurs nametags refuse to keep their renames (but still eat levels and anvils).
Near India, friend on Xbox is in Germany, this started after the XP glitch with furnances was reintroduced.