Anyone encounter this issues while charging IPHONE via iMac?

[Retroworldnews]

the charging cable is original from Apple itself come with the iPhone
I connect via to my iMac , is working condition all ok

than while i connect the cable to my iPhone always can't charge like intermittence
I unplug and plug in always the 3rd time than able to charged

 

[Marc Feldesman]

Is your iMac going to sleep during the charge?

 

[Retroworldnews]

actually nope, I only turn off the display but the com still running

 

[NoBoMac]

No mention of what is already plugged into the other USB ports, but could be already drawing max power with other devices (eg. Portable drives or anything else without its own power).

Can check the draw under "Learn about USB power" at the bottom of this:

If you see USB Devices Disabled on your Mac - Apple Support

Drives, cameras, keyboards, hubs, and other devices that plug into the ports on your Mac can request a limited amount of power.

support.apple.com

 

[Retroworldnews]

No mention of what is already plugged into the other USB ports, but could be already drawing max power with other devices (eg. Portable drives or anything else without its own power).

Can check the draw under "Learn about USB power" at the bottom of this:

If you see USB Devices Disabled on your Mac - Apple Support

Drives, cameras, keyboards, hubs, and other devices that plug into the ports on your Mac can request a limited amount of power.

support.apple.com

I only use one USB port on the iMac that is the iPhone charging cable.

iTune is always up to date Checked
iMac no virus or malware , every hardware is working Checked

the charging cable of course is Original come with the iPhone 7+ which I does still using iPhone 7+

the problem is whenever I going to charge my iPhone via the charging cable connect to my iMac

it will intermittence , show charging than never , got " tong tong sound " Always come the 3rd time after I unplug and plug back than finally charged never show intermittence charging problem.

I even swap the charging cable , same is another Origin one come with an iPhone which previous I used iPhone 6
same problem of intermittence charging when first connect the cable , have to unplug , plug in at least 3 times than charged without intermittence charging problem.