Phil,
As a Trimble dealer we (NEI) see this issue with most Trimble mapping products using SIM cards purchased directly from cellular networks.
We use (DAC) Machine to Machine & IoT Cellular Services | Data Activation Center and have no issues as they are Trimble certified and have AT&T and Verizon at a very fair rate. Their customer services is very supportive if any issues arise.
Chandy Sayre Dealer Relationship Manager
Chandra Sayre <chandra@dataactivationcenter.com>
1.317.644.1286
1.866.966.8881 ( Toll Free US )
Hope this helps resolve your cellular issues.
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Lane LeBlanc
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