Here’s a debugging suggestion:
Use the old TMT, and enable the ATI Level 1 Traces:
(you can probably also do this in M2MStudio - I just don’t know how)
This will let you see the AT commands that WIP is using internally - and, most importantly, any error responses to those commands.
Also be sure that you’ve enabled all the WIP traces - see: Multiple HTTP Requests - every other one fails
You should also check precisely what return code you’re getting from wip_bearerStart - the ASSERT is just telling you that it’s neither OK nor WIP_BERR_OK_INPROGRESS…