Angular Auth0: logged out when calling API after login

I have an issue with the latest Auth0 Angular SDK and the Universal Login.

When I login successfully through the Universal Login and return to the previous page, I am immediately logged out of Auth0 if the page I was on calls my api.

Example:
Have the offiicial Auth0 Angular Sample with a login button on the header and a list of users in the body, which are fetched via api call https:/api.dev.coffeetime.com/userlist

Intended behaviour for this page:
If logged in → fetch data with token attached
If logged out → fetch data without token attached

For this purpose, I configured the httpInterceptor of my Angular environment as follows:

httpInterceptor: { allowedList: [{ uri: 'https://api.dev.coffeetime.com/*', allowAnonymous: true, }]

So when I login the following happens: I am returned to my page and immediately logged out again. The data is loaded without token.

This issue only exists in Firefox (using latest v.92.02). In Chrome, it will keep my user logged in and fetch the data with token.

Any idea what this could be?

Not sure if related but I have lots of “SameSite=Lax” Cookie-Warnings in my Firefox console.