Indeed it was/is one of the issues being reported.
And from the feedback from the community, it appears that this is only a display issue. Meaning, those players that you had blocked in the past are still blocked. However, the display is only showing you as the blocked player.
This was the case for me.
I also did report in another thread that when I clicked in the box for the player name to block, a dropdown list appeared that included the names of every player I had blocked previously. When I tried to block one of those players, the site reported they were already blocked. After trying several, I decided that all the previous "blockees" were still blocked and it indeed is just a display issue.
I just hope when/if WGT "fixes" this, another issue does not arise!