Recently, my custom settings reset each time I go to DU

[NewHendoLib]

I set for no milestones, and political only. These settings reset to default each time I go to another site then return to DU.

This started happening a few weeks ago.

[usonian]

1. See if you haven't gotten into private or incognito mode.

I'm a bit puzzled because doing the above should clear cookies and browser data and I think that

A. would log you off DU, since your login status is stored in a cookie (what else, I don't know ... ) and
B. should NOT change your custom settings, since I think they are stored on the site, not your browser data (could be wrong on this)

Anyway, most problems like this seem to have to do with cookies being cleared.

If you get logged out of DU, then the answer is simple, cookies went away.
Otherwise, it's more complex, and I'm not an insider.

I just solve a lot of problems, most of my own making.

I use a proxy (ICloud Private Relay) and have no or very few problems.
Good luck.

[TwilightZone]

3. Using private/incognito mode shouldn't delete existing cookies.

The site should still work after returning to normal mode. I switch back and forth between normal and private all the time and DU keeps its settings.

In the OP's case, cookies are likely either disallowed for DU in settings or a program or extension is clearing them.

[TwilightZone]

2. That's usually a cookie issue.

Check browser settings to make sure that cookies are allowed for DU. Also check to see if you have a program or browser extension that's clearing cookies periodically and/or when you exist the browser or a site.