So, I tried something new today...

If you seal w/flat coat - you should use an oil based wash - enamel paint mixed w/thinner.
I use oil base washes because they give you a little more time and it will bond to the sealer



or

use acrylic wash w/rubbing alcohol as thinner - not water - be careful that may also eat through the sealer if worked too much

Good luck

I had the exact same issue before! I read about using the same technique and just couldn't get it to work for me at all. Very disappointed... :(

I tried with less soap and didn't get any better luck. I finally took the model in the house and ran it under the faucet, let it mostly dry and tried again with better results.

I always use enamels for my washes now btw. I generally use water-based acrylics for the main color and dry-brushing so I use enamels for the wash so that I don't have any issues about the paint coming off.

An acrylic wash might work. Acrylics have very good adhesion. Just more difficult to remove if you make a mistake.

Sounds like you may have just had too much soap mixed in. Try it with a little less and see how it works.

It doesn't sound like it caused any damage so model on Andy !!!

That doesn't sound good. Thanks for the warning.