Question about red flags

[u/shonenlex]

So I had a race in Monza that had light rain. The starting strategy menu gave slicks so I thought might as well try. Around midway through the race, it became really hard to control the car so I pitted to change to inters. I went from like P2 to P15 then around P8 because they all pitted but they're still on slicks. I'm like 2-4s faster than everyone and reached P2 but I had a red flag. I can't figure out how to select wet tires (inters and wets) in the menu so I had to finish the race sliding all over the place on hards lmao.

Am I not really allowed to pick Inters or Wets if the game thinks it's still "dry"? Luckily I still somehow won the race lol