The device should not be affected electromagnetically.
It may not attach if you are not using a genuine Apple product or Apple licensed product (Made for iPhone (MFi). A magnetic metal, such as iron material cable connector can be used
No, the double-sided tape can not be reused. Please be mindful when choosing locations to place your MAGDOTs. It may also leave marks or residue of the tape upon removal.
Please apply more pressure on the MAGDOT to affix it.