Okay - I've have and continue to use both the Endura T18 & T22 for the past few years . . . Matter of fact, I am using them right now . . . From "My" experience when the light is blinking it is one of 2 reasons . . . Warning - the battery is dying and NEEDS to be recharged (which doen't take long at all) . . . OR - Ya' pushed the button 3 times in a row to quickly (be it to vape all 3 x's or not) - which results in the battery being shut off (same to turn the battery back on) . . . BTW: Thankfully, Innokin did this as a protective measure, given they originally developed the Endura's as a "Starter Kit" to help "Beginners" into vaping (although many advance/experienced users like me still use it too . . .

) . . . As already mentioned by
@Katya- all of this can be found in the "Owners Manual" & "Quick Guide" that Innokin enclosed in each and every one of their products . . . Also, there is the
Innokin Technology . . . You can also contact a few of the Innokin representatives in that thread or even contact
@Innokin_timmy (aka "Lexi") who is extremely helpful and quick to respond (Oh and very nice too . . .

) . . . Just Sayin' . . .
BTW: Although, you can, if absolutely necessary and have no other mod available, vaping while charging - it is not something I would suggest Ya' do . . . Just Sayin' . . .
.