To remove plugin open them as a tiddler and delete yhem, often you will have save and reload but I don't think this is where your problem lays.
Take a tiddler in which you expect the bullets to appear and use the browsers developer tools to inspect the results. This may allow you to see if there is a vas style or class being applied. You can the search for it in the wiki and find where its coming from.
Regards
Tony
html body.tc-body ul {list-style: none;}
html body.tc-body ul li::before {content: "•"; color: #fb0;font-size:150%;
display: inline-block; width: .8em;vertical-align:middle;margin-left:-.8em;}