I'm using Firefox 138.0.3 (Build #2016090503). Duckduckgo.com works fine on my end, maybe something blocking it from your end. Check another browser on your device and another device withing your network.

I'm using iron Fox and ddg search is ok. I can recommend it. It's supposed to have the yucky stuff removed.

I also use ddg but im pretty sure they sell your data to microsoft. Also firefox has been under fire for privacy complaints and censorship. If privacy is a concern you might aswell find another solution.

If you just want it to work Id try waterfox (what i use), or some other fork of firefox that focuses on privacy, ive also heard good things about ungoogled chromium.

Hope that helps

Works fine for me, Firefox 138.0.3 (Build #2016090503). What happens when you try in chrome?

have you tried clearing cookies?