Possible but then that just points back at Jolla for their implementation not working with one of the largest CalDAV and CardDAV providers on the planet. And it of course works with every other device I've got.

Thanks for the pointers with ModSecurity and DAV too but I've been through those already and it works just fine on my Mac and Android and even N9. OwnCloud and cPanel's built in CalDAV works all the time on those too.

...where that single user is Apple or cPanel.net not able to configure their servers?

Or if it's myself configuring my Jolla, I'm unsure how I can manage to connect to the server but entries end up an hour out, disappear when edited or fail to sync.

It could be some protocol difference but I get the same behaviour regardless of which CalDAV server I use.

I don't go on tjc. a) I'm banned after repeatedly complaining about bugs not being fixed but since I'm a Mac user it's b) an exercise in pissing into the wind anyway as Jolla have the same kind of blind spot that Nokia had with Apple.

Simple cure of course for "same names with same complaints over and over" would be to fix the problems leading to the complaints perhaps? Even just a reply saying "Hey, we've (not)reproduced the problem. Thanks we'll fix/won't fix" would be nice.

The people that complain the loudest are often the people who really want a company to do well. We're passionate about making things better. You want those people on your side.