Hi all! I will try to explain the better I could... I have tested it in Montreal (I think it works in every circuit...). When you start a session you have 5 set of "option tyres" (soft) and 6 sets of "prime tyres" (hard). In first and second free practices you can use 2 set of prime tyres and 1 set of option tyres. This 3 sets must be returned to the tyre supplier before third free practice. After third free practice you have to return to the tyre supplier 2 sets: one of prime tyres and other of option tyres. For qualyfying and race you have 3 sets of prime tyres and 3 sets of option tyres. My possible solution is: When you select the tyres for a session you have to select the last set of tyres available in this session. The sets are numbered from 1 to 5 or 1 to 6 depending on the kind of tyres. I have do this in every session in Montreal and without starting with flying lap. For example: In Q1, with option tyres, you have available the sets 3, 4 and 5. I have selected the set 5. I began to race without flying lap. When I had returned to the box the set selected is number 3 and the sets 4 and 5 are 100% OK. Then if you select number 5, when you return to the box, the set used is number 4 and the set number 5 is 100% OK. I think that the possible solution is to select always the last set of tyres available in each session and the bug disappears. I'll wait for your feedbacks to see if this happens to everybody and in all circuits. I hope it helps everybody!