Make sure that the battery is sufficiently charged and the cuff is properly positioned and not damaged. See how to place the blood pressure monitor properly.
If this happens when you are trying to take an Offline measurement, make sure that the Offline measurement function is activated. See how to activate the Offline measurement function.
*credit to Sylvain of iHealth Labs EU
https://helpcenter.ihealthlabs.eu/hc/en-gb/articles/115003934229-iHealth-Sense-BP7-The-blood-pressure-monitor-does-not-inflate