I got caught out by the high power consumption of the LoRa-E5 as well. I’m working on a solar-powered air quality monitor and originally designed it to make use of the RN2483, but as they’re out of stock until 2022 I redesigned it to use the LoRa-E5.
When I got the boards everything went fine until I tried to transmit a message, when everything would reset. I realised it’s probably a power issue, as the LDO regulator I was using (H7333-A) delivers a maximum output current of 250mA. I’m driving both the LoRa-E5 and a MDBT42Q (nRF52832 BLE module) from the same regulator, which in theory should work, as the max power consumption is now 92mA and 12mA respectively, but decided to replace the LDO regulator with a 500mA one and it then worked just fine.
@Charles I found your SeeedStudio forum post but I see there’s no response yet. And also no response on their GitHub repo either 
Looks like I should’ve got with RAK Wireless instead, as it appears like they actually want to fix the problem.