Hello,
No it is not a bug.
Since you have manual shipping method without specific restriction ; even if the user is not logged he can access to some of them.
So in order to fix issues that a lot of people talking about ; HikaShop 3 perform the automatic shipping selection, anytime.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.