Sorry to read about your rough summer.
I had not heard about these problems with Lantus previously.
Fingers crossed you have got to the bottom of the problems.
Unfortunately, I do not always find my diabetes predictable. I guess it is because there is so much that can affect our BG.
Therefore, I try not to draw any conclusion from a one off change: I try it again the next day (or week if it is food related because I get bored with a food type very quickly). If the same thing happens next time, I am happy it was not just a coincidence.
Reading your frustrations over recent weeks, I am rooting for you that you have found the culprit.
If so, have you thought of investing in a Frio wallet? This will allow you to take your Lantus with you and not be tied to the fridge at basal time.