NEW POST and NEW IN FORUM indicators are controlled by timestamps within the FORUM_LAST_VISIT database.
If you recently upgraded from a version of UBB.threads 7.5.9 and older, to version 7.6.0 and newer, then you are probably dealing with the change made in how we deal with times.
Version 7.5.9 and older, UBB.threads used TIME OFFSETS.
Starting with version 7.6.0, UBB.threads uses real real world TIME ZONES.
Because of this change, your entire forum may experience a one-time 24 hour lag in new post indicators while the database catches up to to the time stored within your profile.
NOTE: If your website is telling the browser to cache everything, and your browser is using default settings, you may experience multiple inconsistent results with the new post indicators.
Look for "Header set" in your .htaccess file for information on that setting.
A Cloudflair CDN May also affect stale cached web pages to be displayed. Are you using "BlueHost Cloud Hosting" -- which is basically Cloudflair CDN. Have you customized its Cloudflair settings?
Needless to be said, browser caching and ISP caching could also be part of the issue, but is unlikely in your case, since you mentioned this is a recent issue you just started having
you can request that browsers NOT cache your forum data by inserting the following code to /forums/.htaccess
<IfModule mod_headers.c>
Header set Cache-Control "no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Expires 0
</IfModule>
