I am having this problem also with my new SR357 rack. I had to put spacers under the rear most mount to tip it foward some and under the front two mounting lugs to take up the remaining space to make things work. By doing this the front cross bar can not pull all the way down so that the rubber cushions touch. This is not right but will do for now. I tried starting all the bolts first and pulling it down gradually, but I got worried since this was pulling hard on the bike's aluminum sub frame, so I stopped before something broke. There seems to be a fitment problem whth this rack. My factory plastic grab bar fits perfectly. If the bike were screwed up that would not fit. Mine came from Twisted Throttle, but was shipped directly from Givi warehouse.
There are damn few things I would claim to be an expert on. I've looked for answers on this forum many more times than I have offered them.
There are two topics I am very familiar with. One of those is the rear subframe on the FJR. As someone who has designed items which attach to the FJR rear subframe, I can tell you there is a bit of variation from one GenII bike to the next. The variation seems to be even greater between model years.
That being said, I'm aware of zero GenII rear subframe failures. Out of zero failures, none have been caused by the excessive preload Givi SR357 rack.
I would not start all of the screws through the Givi rack at the same time. You may damage the threaded holes on the bike if you do this. This is what I would do:
Use anti-seize on the threads.
Snug the three rearmost screws through the rack first.
Then, press down hard on the front cross member of the Givi rack.
Thread the remaining two fasteners and snug them down.
This will give you the best alignment and cause the least damage to your threads. If you start shimming the rack, the holes will not line up as well and the screws will damage the threaded holes in the bike's rear subframe.
Before you snug down those front two fasteners, it might also be a good idea to take a photo of the gap between the front cross member of the Givi rack and the bike's subframe. Then, contact
https://www.giviusa.com/Contacts/
Your message will be forwarded to Paul Collins, GIVI USA Inc, Charlotte, North Carolina
-Joe