Hopefully there's hope in sight!!!
https://community.sprint.com/t5/Pho...-S10-10-Model-Roaming-LTE-Issues/ta-p/1038563
Quote
"4/12/2019 UPDATE: As always, Sprint and Samsung continue to closely monitor concerns about intermittent or total loss of voice or data with the Samsung Galaxy S10, S10+, and S10e handsets. There will be a software release available on Tuesday, April 16th that will prevent the device from experiencing intermittent voice or data. Please update your device as soon as this release becomes available."