I also found that if i changed a form style it affected other pages on my site, even though i saved it as a different preset name.
I somehow was able to get around this by saving the preset to the first preset name of several I had created. Maybe the first name is being used as a default?
I don't know if it is related, but when I select to save the style as a preset, i get a bunch of errors, until it finally accepts the name of the preset.
Thank you