@John *********
you don’t need an employment contract if it’s your own business.
In my case, the (yearly) tax return and the balance sheet of my company was enough to prove my business is legit, profitable and that I’m the only shareholder. There is no employment contract and no personal, regular income.
I did include a portfolio explaining which business I’m doing through my company and why I can do it remotely.
To the OP; one quarter isn’t enough. Tax returns of the previous year, your balance sheet and a personal bank account with a balance of the equivalent of 500,000 THB should do it. Together with your portfolio explaining what you do.
The rejections can be for multiple reasons; your travel history to Thailand, insufficient funds, lack of authenticity of the documents you provided,…