This is primarily due to negative pressure in the diffuser. Because the diffuser is activated by drawing through the mouthpiece, if you instead blow into the device (whether by accident or on purpose), it can cause the diffuser to activate in an irregular fashion. For this reason, we recommend that you do your best to avoid blowing any air into the device, as over time that can limit the lifetime of the diffuser.
However, it could be due to overuse as well. Make sure you are doing your best to stay within the usage guidelines, as the diffuser will automatically begin blinking if it's been used to rapidly in succession.
If neither of these seem to be the issue with your diffuser, we would be happy to help troubleshoot with you. Please send us an email at firstname.lastname@example.org and we'll be ready to take care of you!