I found a thread on an online forum where someone had the same problem and it was solved by using a different email address so you could try using a different email address and see what happens. If you don’t have an alternative email of your own for any reason you could “borrow” one from a family member or friend. Also if you are using a VPN try turning it off.
I have had trouble in the past using my usual truemail email address on Thai government websites like TM30 and 90 day report. I have no idea why but I created a gmail address and used that without any problems so you could try that. I also always use Chrome browser.
Out of interest when did they start putting non IB on entries under a non B visa? In the past I have had many non B visas and in every case my entry stamp was marked non B.
It might be worth pointing out that depending on your future plans getting an overstay on your record might not be a good idea. I know for a fact that when you apply for a Thailand Elite visa the application form asks if you have overstayed in Thailand in the past 3 years. I don’t know if it affects you in any other ways.
Exactly. When I left my last job I got a slightly odd “ not approved” Extension of Stay stamp giving me 7 days to leave the country after submission of my WP cancellation receipt to immigration. I don’t recall what form I submitted to get the stamp as it was prepared by my employer HR manager but I remember paying the 1900 Baht.
I try to do the on line report 14 days prior to the due date as you mention because if it fails it leaves you plenty of time to schedule an in person report before the due date. You could also do a report by registered mail but the Immigration website suggests sending it 15 days prior to the due date and they recommend contacting immigration if you don’t get a reply within a month. Don’t forget to include a self addressed envelope with a stamp if you do this otherwise you will never get a reply!