Don’t worry, this TB is probably NOT lost. But tourists (and tourist-cachers!) in Amsterdam are notoriously slow in logging their finds and grabs. So it often takes more than a month before someone takes the effort to log a TB.
In the mean time, the cache has a long list of TBs that aren’t there anymore. This is confusing, so after a couple of weeks I mark them as missing, only to remove them from the cache. When the cacher that has it logs the TB it’s back in action again. Happy caching!