I believe I found the root cause, as you have configured your account not to show bot accounts.

the lemmy version used on lemmy.world does not currently filter those out, even though they are not shown in the actual message view.

this was fixed for a newer lemmy version already, but it should be a rather simple backport.

i've put it on my list of potential backports.

meanwhile you can try enabling showing bot accounts in your account settings and you should see all those messages. feel free to disable it again afterwards.