Due to a missing slash, Magnolia does not determine the lastUpdateTimestamp of the cache correctly, which leads to an entire cache clear at module (re-)start.

Here's the relevant code snippet:

https://git.magnolia-cms.com/projects/ENTERPRISE/repos/advanced-cache/browse/magnolia-advanced-cache/src/main/java/info/magnolia/module/advancedcache/NotifyFlushListeningPolicy.java#138

                if (!session.propertyExists(path + TIMESTAMP)) {
                    cache.clear();
                    timestamp = System.currentTimeMillis();
                } else {
                    timestamp = session.getProperty(path + TIMESTAMP).getLong();
                } 

Path, which is something like /NotifyFlushListeningPolicy/defaultPageCache is concatenated with lastUpdateTimeStamp and this leads to property lookup like /NotifyFlushListeningPolicy/defaultPageCachelastUpdateTimeStamp which obviously isn't a correct path. There's a slash missing right before lastUpdateTimeStamp.

The consequence of this is, that even a persistent cache is flushed entirely upon restart.

Please patch the code with:

                if (!session.propertyExists(path + "/" + TIMESTAMP)) {
                    cache.clear();
                    timestamp = System.currentTimeMillis();
                } else {
                    timestamp = session.getProperty(path + "/" + TIMESTAMP).getLong();
                }