Grade course total not calculated properly with grade items

I recently updated an existing test whilst implementing some new generators in MDL-74613. Before my changes, the test only tested submission grades and the total grade was correct. However, I added a grade item to test that as well and the total grade does not seem right. I'm not sure if that's the expected behaviour for some obscure reason I don't grasp, or if this is actually a bug.

I tried to look at the code to understand how that value came to be, but after finding a discouraging comment I decided to stop digging any further. I think it's better if someone who understands this more in depth takes a look.

The test in question to reproduce this situation can be found in the switch_views.feature file.

I'm also attaching a screenshot of the page to show what I mean. Looking at that table, I'd guess the total should be 110. So I'm not sure how 105.71 is calculated.