I had problems with Parler yesterday, which have now seemed to have cleared up.
I am having problems with Gab right now, just as you describe.
Neither platform was prepared for the onslaught of new accounts that have happened in the past 48-72 hours. Both are very small “mom and pop” platforms running on a shoestring, not unlike Free Republic.
Hang in there, it will get cleared up. Don’t expect Twitter-like ability to handle tremendous spikes in traffic immediately. They will need time (and money) to expand their capacity.
I think it's cleared up because people have given up trying to login. Parler dropped the ball by not being prepared for the Twitter exodus, which has been foreseen for a while now. Probably lost millions of sign ups yesterday after Trump was banned. It remains to be seen if they'll be able to recapture the crowd...once you have a customer in your store you have to close the deal. Parler may turn out to be MySpace if another platform comes on the scene like Facebook did to end it.