Form won't submit with decimal value

I have a form which has a field for currency which won’t submit with decimal values. The mysql database fields are decimal (8,2). There’s no error, the field just glows blue. If I remove the decimals it submits. Any pointers would be appreciated. I’ve tried recreating both the server action and the form to no avail.

Another anomaly, with that same field I have to convert it to number to format as currency on output. purchase_price.toNumber().formatCurrency(’$’, ‘.’, ‘,’, 2). If I don’t have the toNumber() it doesn’t output.