Guild Wars 2

So I haven’t been playing for about a year now. Me and a few friends had a guild together and the bank was full of various things we all trusted each other with.
I come back to the game with the release of HoT and find that the stuff that was in the guild bank is no longer there. We all quit at the same time, but more importantly, the log doesn’t have any record of who withdrew the items. Or, well, any record of anything.

So my question is, as the title implies, is there an expiry date for the information the guild bank log displays? Or maybe it’s something else?

Also when hot launched and the new guild system came it the logs were purged as well.

I find sometimes during patches and server crashes the log gets cleared. Its not 100% reliable.