Samsung Galaxy Tab Active Pro SM-T547U In A Ram Mount Tough-Case For Tab Active Pro Charging

I have a Samsung Galaxy Tab Active Pro SM-T547U tablet in a Ram Mount Tough-Case for Tab Active Pro. It has a power cord with a USB-A connector. My wife and I used it yesterday in our Can Am Maverick running the Polaris Ride Command Android app. In the Maverick 12 volt power outlet I have a Scosche dual USB car charger. The car charger is marked on the side:

Input: 10-16VDC 2.9 A

Output: 2.4A Per USB Port

When we used it yesterday the Samsung tablet showed that it was charging, but the charging never kept up. In other words, even though it showed it was charging, the battery percentage dropped during the ride.

I am now trying to determine what is causing it and how to proceed. It is possible that the Can Am is giving less than 2.9 amps at the power outlet that the Scosche needs. I suppose that can be measured with a multimeter.

The next possibility is that the Scosche dual USB car charger isn’t really putting out the 2.4 amps that is claims. Can that also be checked with a multimeter?

I now want to try a different car charger that has at least one USB-A that puts out enough power to charge the Samsung and keep it at 100% battery.

I do recall reading that 18 watts per per is the maximum that a USB-A port can deliver.

I am considering a Ram GDS Type-C and Type A 2-Port Cigarette Charger, Samsung Adaptive Fast Charging Vehicle Charger or an Anker PowerDrive Speed+ 2 Car Charger. From the looks of it, any of them should work equally well. Any other considerations that I should be aware of?