It's a client issue. I've noticed some clients only fetch a few relays, typically the fastest ones, even if you have more than 20 configured. For instance, the #noStrudel client by default only checks the 4 fastest ones. Sometimes, your note may not be included in any of these selected relays and will result in it not being displayed in that specific case. I assume #Primal functions similarly. I tested on #Snort and your note appeared correctly, but on noStrudel didn't (unless I configured it to fetch all relay).