I've been using the Symbaloo extension (bookmark tiles), such that every time I open a new tab my tiles appear. However, I recently had to disable all of my extensions due to a computer problem. When I enabled them again, I lost Symbaloo, unless I directly went to the symbaloo URL

I managed to solve this via the custom new tab page extension, but first had to deal with the Firefox page telling me to deal with an embedded issue by clicking on 'open in a new window'. Now it works, but not in Private Browser. When I click on the + to open a new tab, the Firefox search page opens. How can I fix it so that Symbaloo once again appears in the new tab in Private Browser, as it did before, and as it is now doing in public browsing? Thanks.