The JATCO CVT7 is a two speed CVT gearbox with a high and low range. Everytime you start from a stop the transmission starts in "B or L (they are the same thing)" even when the gear selector is in "D or Ds". It upshifts from the low range into the higher range ratios at a low speed usually around 15 mph so you might not notice it. When you come to a stop and sometimes you get that "lurch or that weird delay from a stop" that's the CVT shifting into the low range. Shifting it manually from "B or L" into "D or Ds" or vice versa is just you the driver deciding when to change gear ranges, not the computer. JATCO even put out a handy little video to demo how the system works.
This article talks about using the CVT ranges more aggressively.
https://realworlddrive.wordpress.com...he-mirage-cvt/