There sometimes an a rectangle option in the top left of the address bar, press that then the three dots at the bottom right and there should be an option to request desktop website. Not saying it will work but it might.
Depends when you fly out. As long as it’s 90 days total until Sept 19th you’ll be fine. If not you’ll have to leave Thailand a bit earlier as overstaying is 500thb a day fine and can mess up your chances of other visas in the future.