There are embassies that allow a final balance of 500K plus 6 months of statements at time of application. You have over half the 500K so nearly there.
I can't think of any other reason apart from what's been mentioned. As you/others noted it is essential to double/triple check before submitting due to the site's faulty reading of passport data.
I contacted Taipei about not being able to provide company registration and was told 'Ok, bring what you have on the company". Your recent experience freelancing should not be issue as there is no income requirement. Make sure you bring the statements showing your payments that match the invoices.