I entered Thailand on 8/31 with my Non Imm O visa which had a issue date of August 18 and and expiration date of November 17. When I went through immigration they stamped me in until November 30.
I know that I need to apply for my 60 day extension based on visiting Thai family within the 30 days before November 17. My question is do I need to go to immigration before that to fix the discrepancy with the entry stamp?
TLDR : Answer Summary
After entering Thailand on a Non Imm O visa, you were stamped until November 30, which is correct as it indicates your allowed stay duration. The visa expiration date of November 17 pertains to when the visa must be activated, while the entry stamp duration is what matters for your stay. You can apply for a 60-day extension for visiting family before November 30 without needing to correct any stamp discrepancy.