I thought the same when fitting one to mine.
It looks like it's not going to fit and even came with instructions suggesting that it won't look like it fits. I had to flex and manipulate mine to put it in place, which it did nicely. Although was a 2 man job.
Mine is an SSDD Carbon diffuser so again reputable. I'd suggest this is normal and give it a go.. It'll get there after some persuasion.
It looks like it's not going to fit and even came with instructions suggesting that it won't look like it fits. I had to flex and manipulate mine to put it in place, which it did nicely. Although was a 2 man job.
Mine is an SSDD Carbon diffuser so again reputable. I'd suggest this is normal and give it a go.. It'll get there after some persuasion.