Sorry, You already said that the UI works.
You only need the Driver, Server and Database entries for an SQLite database, Port, User and Password should not be set.
You should take a step back here and rethink, what you are trying to do here! It will not work!
You are using sqlite as token database in pi.cfg. Why? You know that sqlite usually can only have one concurrent connection? You should not use it, unless you know, what you are doing.
You are configuring a user resolver, on the same sqlite database? Why? (see above).
You should be careful with using sqlite. If you are using the same sqlite database as token database and additional userstore, this will most probably fail. The thing is, you are very sparse with log information. We are back on square 1 with guessing.
If you really know what you are doing and you need to use sqlite with everything (did I say you should not use sqlite in a productive environment with more than one user?), then you should at least put your users in another sqlite database to avoid connection blocking.
Take a look at the tool privacyidea-create-userdb. It creates the sqlite database and the sqlresolver configuration.