Just had almost exactly the same experience.
In my case, my active build was leveled up but I had recently switched back and forth from an inactive build.
I lost about 1/4 of my enhancements on the first try and about 1/2 on the second.
My chat window was filled with lot of purple nonsense characters (sorry I forgot to take a screenshot)
I logged out but had difficulty reconnecting due to a mapserver failure
Eventually, however, I was able to log back in
As OP reports, after logging in again I was able to respec and got all my enhancements back.
Also, I'm not sure if this is behavior as intended (maybe it's a new quality of life feature?), but I noticed that respec now lets me place my slots in any order, including into powers that would not be allowed to have that many slots if leveling up normally (for example, I could 6-slot my last selected power if I wanted to). However, I was careful to place my slots in the valid build order I had originally planned.