Can you check if you have the System - Cache plugin enabled? If so, please ensure it's the last plugin in the list (highest ordering number). If it's in the wrong order, the page output can be cached before we replace those tags.
If that's not it, please try disabling all caching in the Joomla Global Configuration area, the JCH Optimize plugin, and any other optimization or caching extensions you may have enabled. Then, see if that fixes things. If so, start re-enabling them one-by-one to see which one is causing the issues.
Once we narrow things down, we'll gladly try to help fix the issue and make everything work well together.
Thanks,
Alex