Will Thai immigration accept my extension of stay in my old passport when I enter Thailand with a new passport?

I tried to get visa stamp moved from one passport to another in Jomtein. They refused because old passport had not been officially cancelled. (Still valid for three months). May not be the same in other offices.

My new passport has a note on the last page indicating the passport it replaced. I am wondering if that would suffice.

Enter Thailand with both passports. Be sure to check entry stamp is with the re-entry permit for Non-O, the same duration as your extension before you leave the passport control upon entry. Once in Thailand, go to the immigration office that issued your extension to move stamps. You don't need the letter to move stamps from your old one to your new passport when you get a new passport in your home country.

When you return to Thailand, carry both of the passports with you.

Show the Thai Immigration Officer upon your arrival the One year extension of stay stamped in your Old passport...

The Thai Immigration Officer will stamp you into Thailand in your new passport for the time remaining on the extension of stay stamp in your old passport... November 30, 2023.

Hopefully your New German Passport will come with a letter stating that it's a replacement of your current passport.

IF not, get your German Embassy in Bangkok issue such a letter to Thai Immigration asking them to accept your New passport.

Go to your local Thai Immigration office and ask them to transfer your extension of stay into the New passport.

Be sure to have a re-entry permit in your passport when you leave Thailand.