My friend Sergey Kuznetsov in Facebook wrote a good post for everyone who has Z3, I knew about buying a plug, but did not know about a refrigerator (smiley). I hope it will be useful for you too. And, yes, it's very good that the Z3 + has no problems with the microUSB port plug, every time I remember the Sony engineers with a kind word when I put the device on charge.
'Here's a little life hack. On Xperia phones, over time, the rubber band on the end cap becomes unusable. Without it, the phone can no longer be wet even in the rain. For some, this elastic band comes off completely, for someone it simply starts to move away from the plastic in places. To fix it, you don't have to drag it to the service or change your smartphone altogether. The plug can be easily removed from the body. Pull lightly on yourself and begin to rotate around the axis, at a certain moment it will pop out. Then buy the same plug. Available in almost all computer / telephone markets in Moscow. Issue price: 500-700 rubles for two covers (for SIM and MicroSD). Insert back in exactly the same way. Press and twist. To fix the Xperia Z3 Compact, I spent 1 minute disassembling and assembling, 650 rubles for parts and 30 minutes to get to the store. But now the plug fits exactly into its place, does not fall out and the phone can be dropped into the water.
By the way, if the rubber bands are in order, but the plug still does not snap into place, then at first you can simply clean everything from dust and put the plug in the freezer for 5-10 minutes. After that, she gets up like a glove. But if the gum fell off, then this will not help in any way.
PS: I envy all the owners of Sony Xperia Z3 +, because they will never have such a problem, and indeed this is the best phone right now. '