Admin Passwords stop working ?!

Hi guys,

I am in the process of upgrading some etomite websites to modx evolution.
I have been working on these sites extensively yesterday. I have experienced passwords that just stop working at several occasions.
First of all, after doing a clean install of the system I enter a password for the administrator.
When I try to log into the system immediately after this the password does not work. I am 100% entirely sure that I used the same password and I am able to reproduce this issue. The used password contains a non-numerical and non-alphabetical sign, which I think causes the issue.
After resetting the password and logging in, I van change the password to the one I want. It worked for a while, but today it stopped working again.
Is this a known issue or is there something that is possibly configured badly on my site (which seems unlikely)?

edit: to be clear: this is happening on 4 websites (all on same server), all passwords worked fine yesterday and stopped working today.

I narrowed this problem down to the use of the ampersand sign (&) in the password.
For some reason modx does not seem to be liking it.
Bugreport?

https://github.com/evolution-cms/evolution/issues