Passive check results don't always show up on the web page

I have an annoying problem - not all the time, but mostly after I have reconfigured icinga2. This is what happens:

I have a number of passive service checks - they all work well, and I see updates on the web pages. Then I make a change, eg. I create or rename a service group, and restart the master server, and all the passive checks disappear (this is not the problem, although it is a bit unnerving) - they normally come back again after next update, because the passive checks create them again. However, quite often they don’t show up on the web page.

I can see in icinga2 console --connect 'https://some:body@master.server.com:5665/' that the service objects exist and look normal - they just don’t show up. Is there any way to force the issue? Or figure out what is wrong?

===EDIT===

I ran the master and the satelite zones with debug, and I saw that they both made references to a service I have renamed - ie, there were lines like this in the debug logs:

[2019-03-08 11:44:21 +0000] notice/ConfigCompiler: Compiling config file: /var/lib/icinga2/api/packages/_api/cx1-admin-1521551477-1/conf.d/services/cx1-136-5-2.cx1.hpc.ic.ac.uk!check_xfs.conf

I cleared all of them out, and that seems to have made a difference.

How exactly did you rename that service? This one was created at runtime, thus requiring a DELETE and PUT again.

That was indeed what I did - I changed the name in the scrpt that creates and updates the services, which left me with a lot of service objects with the old name as well as the ones with the new name; I then deleted all the old ones.
However, it seems what breaks the setup somewhat is that when I create a new service group, the satelite somehow doesn’t understand what is going on (see Passive checks not updating for 2 days), and I have to delete stuff. I create a service group for each service, or as in this case I renamed a service group to follow the renaming of the service object. It seems the easy fix is to go and delete the hosts/ and services/ directories found somewhere under _api.