PH Probe Calibration Issue INTP 5210 Pentair: Urgent Replacement Request

Client:
Hello,
Yesterday, I tried to install my new PH reference probe INTP 5210 for Pentair that I ordered from you on July 17th (order YXVOZRUWM / invoice FA009287), but "despite several attempts" it appears that it cannot be calibrated!
The first calibration step in PH7 liquid goes well, but the second calibration phase in PH4 liquid FAILS EVERY TIME (see attached photo).
I would appreciate it if you could replace this defective probe as soon as possible.
Thank you for your prompt attention.
Best regards,
Patrick PENAUILLE
06 07 02 00 05

Technical Advisor:
Hello,