This not a report about the list scrolling up all the time – please post that separately.
Previously transferred characters are sometimes not showing up in the guild roster. Furthermore, when they speak in guild, some people see them as having their old realm names with a suffix.
And it’s not just a recent transfer, either. For example, a guild mate said that they saw my mage have a “-Rexxar” suffix, while my mage went from Rexxar to Hydraxis about two years ago, and we’re now on Stormrage.
There have been other such reports from back in October/November of last year: Characters in Guild Roster appearing as from different server
And this was apparently fixed at the time, according to this help article: https://us.battle.net/support/en/article/000320126
This bug is present for me in-game as of yesterday, March 2nd 2023, and I have heard multiple reports of it from other guildies as well.