Search query not working as expected

I have quite a lot events in my google calendar but I tried using the search query to show only two types on my webpage:
– PG: (Whatever the event name)
– HG: (Whatever the event name)

Now typing PG into search query field shows the PG events. Same applies to HG. But using simple boolean operators PG | HG (or PG AND HG) doesn’t work at all. Am I doing something wrong or …?

Here is the google calendar: https://calendar.google.com/calendar?cid=MDJyODY3dHU0NnBmb2Ewc2Nxcm1tdjN1bzBAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ