Digital USB -C multi port adapter

As per Apple's product page, the adapter is definitely supposed to charge via USB-C the device while using the HDMI output port and, in case, the regular USB port (input/output):

USB-C Digital AV Multiport Adapter - Apple

Your iPads are listed as compatible with the adapter.

You said they are 12 months old. Is it the first time that you experienced the charging issue or did they work in the past 12 month and only now you encountered the issue?

As LotusPilot said, it's probably a current-related issue (ampere).

I've found a thread addressing a similar issue with the adapter (using a Mac in this case):

https://apple.stackexchange.com/questions/419478/does-the-av-multiport-adapter-charge-big-macbook-pros

It seems that the adapter "reduces" the current flow.

Here's and Apple's page containing further specifications about the adapter.

About the Apple USB-C Digital AV Multiport Adapter - Apple Support

Be aware that most models of iPad require a Power Adapter rated at 12W or greater to reliably charge. 5W Power Adapters intended for older models of iPhone are inadequate to charge an iPad; if the iPad charges at all, charging will be very slow.

When using a Power Adapter with your USB-C Digital AV Adapter, you will require a USB-C Power Adapter that supports USB PD (Power Delivery), rated at 20W or greater. Apple USB-C Power Adapters support this standard. If you are using a third-party Power Adapter, check its specifications; if the Power Adapter does not support USB PD, it is unlikely to be suitable.

cherubshirl wrote:

Hi Lotus Pilot, now I’m not sure if I have tried a 20 W power. I will buy one and see if that works.

As your iPad has a USB-C port, it should have been supplied from new with a standard USB-C 20W Power Adapter.

If purchasing a new Power Adapter, an Apple 30W USB-C Power Adapter may be more useful - as this has sufficient capacity to both power the AV Adapter and similtaneously charge the iPad at its maximum supported rate (20W). The “spare” 10W can usefully power the Digital Multiport Adapter and, if used, additional USB devices connected to the USB Type-A port.