Unstable Pressure ¦ Fluctuating pressure ¦ Build Pressure-Redose many times

While I was running a full isotherm in the desorption branch, the instrument started to Build Pressure-Redose many times for a single point (more than 20 minutes, to measure one single point in the desorption branch). Anyhow, the analysis was completed, and I proceed to the next sample in order to degas it. First, the degas settings got stock while "Evacuating System" or perhaps while "Evacuating Cell". So, I aborted. The next significant steps that I took was, Zeroing the Transducer (The Pressure continued unstable, fluctuating between above zero and below zero mm Hg in more than 100 or even 200 units). So, I decide to Span, with an atmospheric pressure of around 750-760 (The Pressure continued unstable, fluctuating between above zero and below zero mm Hg in more than 100 or even 200 units, reaching above thousands to - thousands of mm Hg.) Because of COVID we cannot proceed to technical visit support, and at the moment is not for my company an option shipping the instrument. Please, could someone let me know if you have ever experienced, "Unstable Pressure ¦ Fluctuating pressure" in a very spread pressure range, and how did you address the troubleshooting? Best Regards