You probably just need to change the batteries in both units. My son had the same issue with his.

Eventually the rechargeable batteries get to where they won’t take charge anymore. Gun dog supply carries the replacement batteries.

Majorly Reduced Range; Getting only Several Feet/Yards and then Stops Working

- If your system works within a few feet (maybe 15 feet or less), but then stops working abruptly, it is very likely that some sort of physical damage or heavy impact has occurred to either the handheld or the collar and it has failed. If it has malfunctioned in this way, the dog device or the handheld or the system may need to be replaced.
- If no physical damage occurred that caused the issue, it could be other internal device issues or failure. Either the handheld or the dog device or the system may need to be replaced.

To help identify which of the two devices has malfunctioned, pair the handheld to another collar, and/or pair the collar to another handheld.
- If you do not have extra devices, a friend or family member that has this equipment, can help. Ask them to cross pair one of their compatible devices to help diagnose the issue.
- If you do not have other equipment to test with, contact Garmin Product Support for information and guidance on replacing the individual devices or entire system. Please have serial numbers available when you contact Garmin Product Support.

i have the garmin pro 550. not sure if that would be any help to you to try or not,

I appreciate ya, but I finally got it resolved. It turns out it was the collar.