Is it a problem to enter Thailand with a DTV on my Philippine passport after receiving my British passport?

Take both passports with you, on dtv it has passport number its issued on. Later when you arrive, go to immigration/embassy (cant remember which) to update the passport number on your visa

Entering Thailand on a visa issued in one passport while using another can indeed lead to complications at immigration. If you've applied for a Destination Thailand Visa (DTV) with your Philippine passport and now/soon hold a British passport, it's advisable to carry both documents. When you enter Thailand, you should present the DTV along with your Philippine passport, even if you're traveling on your new British passport. This ensures that your visa status is clear to immigration officers. However, for peace of mind and to avoid any potential issues, consider informing the Royal Thai Embassy about your change in citizenship. They might offer solutions like transferring the visa to your British passport or suggest reapplying. Always having your travel documents in order and aligned with your current citizenship status is crucial to ensure a smooth entry.

Enter Thailand on your British passport you’ll get 60 days visa exempt. Enter on your Philippine passport with DTV you’ll get 180 days.

The DTV being issued as a pdf file doesn’t mean it’s not tied to a specific passport. The passport details are on the visa, you won’t be able to use it with a different passport.

If the DTV is in the Philippines passport enter on that. You will not have a DTV on your British passport will you. I am assuming your are keeping both passports and not renouncing Philippines citizenship.