guys, i did some troubleshooting and managed to identify something

symptoms:
1 - click "sign in" link but nothing appear, but the "join now" link working fine
2 - sign-in box appeared, but after key in username/password the page will be loading forever
3 - this only happened to the browser i frequently use, if i open(/install) another browser and i can sign in without issue

possible root cause:
1 - after price check, or we entered the final payment page, then somehow we decided to abandon the reservation by closing browser or simply let it timeout, so the open session still running
2 - if we try to login again, we will get login problem, like sign-in button not responding, or login page loading forever

possible fix, you all should try:
1 - clear cache/cookies, and must change your IP.
2 - there are several methods to change IP, restart your modem/router, use your mobile phone to share wifi hotspot, or VPN
3 - if you dont know how to change IP, just install and use a new browser. (firefox, opera, chrome, edge)
4 - if you dont know how to change IP, install new browser, you can wait a few hours or days, wait till the session be closed, then you can login back as usual.

Please try this method and let me know if it works