Wrong session theoretical best at the end of a Time Trial session

So I was doing laps around Imola in Time Trial to prepare for a league race. I finally got a time I was happy with and stopped (on lap 38). The lap was by no means perfect so I quickly checked the race director to see if I had managed to PB at least one sector on that lap.

I didn't. S1 PB was 23.702 (lap 34) [see attached "RD1"], S2 25.361 (lap 17) & S3 24.721 (lap 18) [see attached "RD2"]. After that I ended the session and wanted to see what my theoretical best laptime would be. But when I checked the end of session screen, I noted that the sector times displayed for both S2 & S3 aren't actually my PB for those sectors [see attached "EndScreen"]. If you add the 3 sector times that are displayed, the time is correct sure but since those are not my best sector times, the theoretical best lap isn't correct.

I very strongly suspect that the theoretical best lap time doesn't actually count your best sector times but only takes your best sectors from your fastest 5 laps. I came to that conclusion as my PB times for S2 & S3 were recorded on laps that aren't in my 5 fastest laps. 

It's not the first time I run into that situation (it happens on other tracks too) but it's the first time I actually take time to verify whether my intuition is correct or not. And it turns out that there is actually a problem.

Hoping for this to reach the devs team.

Thanks for reading!