I'm tethering my Trimble TMX-2050 to an iPad hotspot for RTK corrections through VRS. It works great about 95% of the time but several times per day the hotspot disconnects and the unit falls into X-Fill.  I run a similar setup in my sprayer but connect to a Back40 Precision RTKonnect.  It has zero issues.  I'm guessing the WIFI dongle I'm using on the TMX is my issue.  What are the recommended devices?