A USB Accessory Charges but Does Not Connect to Your MacBook
On a Mac laptop with Apple silicon, charging and permission to use an accessory are separate. Apple documents that an accessory may still charge the Mac even when you decline its connection request.
Look for the approval request
Unlock the Mac with its built-in display open and connect the known accessory. Read the prompt carefully and approve it only if you recognise the connected device. A dock can introduce several connected functions, so note which of them becomes available after approval.
If you previously chose Don't Allow, disconnecting and reconnecting the accessory gives another opportunity to respond. Save work and eject any mounted storage before physically disconnecting a dock that also carries disks.
This check is specifically relevant to Mac laptops with Apple silicon. Do not assume every Intel Mac or desktop Mac uses the same approval behaviour.
Keep the security choice intentional
Review the accessory connection setting in Privacy & Security; on current releases it appears under Accessories. Apple offers choices ranging from asking each time to automatically allowing connections. You do not need to choose Always Allow merely to make one trusted device work.
On a managed Mac, an administrator may control this setting. Record the message and ask them to review the intended accessory rather than looking for ways around the policy.
After approval, test each needed function: keyboard input, a mounted storage volume, network access or a display. If only one remains unavailable, permission may no longer be the limiting factor. Record the exact dock, host cable, Mac model and failing function for the next compatibility check.
For a desk setup used with the lid closed, approve the display and input devices before closing it. That avoids trying to answer a permission prompt on a screen you can no longer see.
Source: Apple's accessory approval guidance.
For help with your Mac, contact AEPC in East Auckland or call 027 908 8880 to discuss your requirements.