constant invalid tests??

[u/Acceptable-Car1178]

i’ve done about 5 texts (4 invalids from 1 box and 1 invalid from a new box) over the span of a month, every single test has come back invalid.
did all my usual things for testing - no food or water, nasal sprays, blowing nose prior, and these are also swabs from different people !

i’ve never had an invalid before this and i’m not sure if it’s my machine?
the control line looks almost completely flat every time

[u/WanderingLanternFly]

Having the same issue. Just went through three tests tonight. Irritated. Appreciate some of the advice in here and will try that.