I recently purchased a 1/2" garden hose and two hose fittings (not native English speaker, this is what the English version of the store's website calls them - image attached) which according to the packaging are for 1/2".
The problem is that the hose is really difficult to connect to the fittings, it's a really tight fit, and I can only get the horse pushed about 5mm over the connector. This is barely enough for the locking mechanism to be able to press against the hose, but when the water is turned on one of the fittings eventually comes lose. I assume I need to push the hose further over the connector.
I've tried to use WD-40 to lubricate the hose and connector, but it didn't really seem to help. I also tried to expand the hose by using pilers, but that didn't really work.