All facets/filters might not be visible under Assets in the left sidebar whereas trying an Advanced Search, tried in the same session or a different one, for a similar keyword brings up all the facets. This is observed even if all the assets are tagged correctly. The sum of the results next to each facet in a group may not even add up to the total number of results returned.
This is caused due to TeleScope not setting the number of facets to be returned when it queries Solr, and thus Solr defaults to sending only 100 facets. This happens when doing a faceted search, that is, clicking on Assets, or selecting/unselecting facets from the left sidebar after clicking Assets. Advanced search doesn't have this issue.
Steps to Fix
This issue was fixed in TeleScope Standard 2020.3. Since this is a bug in how TeleScope queries Solr, re-syncing Solr won't help in this case and it is recommended to upgrade to the mentioned version or later to fix this issue. If your TeleScope installation has customizations or you're an OnDemand customer, please contact your Account Manager or support for further assistance with the upgrade.
After upgrading TeleScope, please check that all the facets are visible when you click on Assets or do a faceted search from there, and also that no additional facets are visible in Advanced Search.