Yes lots of threads on this problem but the easiest solution is shut off valves on the overflow outlets.
To avoid forgetting to open them before filling I put a note on the "arrival" checklist to open all of the valves. That way they were open for the next fill. Nothing worse than dry camping with a 125 gallon water tank and finding that you only have about 60 left when you arrive at your location.
2018 Jayco Greyhawk 29MVP
2019 Jeep Sahara Unlimited
2011 Cyclone 3010 Toy Hauler- Sold
2014 Chevy Silverado Duramax LML -Sold