I have recently the torhans vr bottle, in fact I purchased three of them.
I'm happy up to now and in fact I was surprised how well the rubber cap attaches to the plastic body, indeed quite watertight.

BUT.

Now I noticed, that two of the rubber caps (the only two I used: not too often though, maximum ten rides) are getting out of order: the cross-cuts at the top deteriorate in that the cuts brake further into the cap.
Am I the only one with this problem, is it because I put them in the dishwasher or is it generally a weak point of the caps?