Brake pedal pulsation with audible solenoid click

so my 2018 GEN four Toyota Prius when sitting at a stop whether it's cold or hot intermittently will send pulsations into the brake pedal and a solenoid click can be heard at the same time.
It doesn't happen all the time that's gradually having more and more. I understand that accumulator failures are rare on these, but of course it has me very nervous. the intervals of pulsations and clicks can be between one every second to sometimes twice a second. I have yet to hook it up to a tech stream.
has anybody experienced anything like this?

 

Observed behavior:
• Clicking only occurs with brake pedal depressed
• Clicking stops immediately when pedal released
• Occurs only in READY mode
• Audible clicking heard inside cabin
• Synchronized pulsations felt in brake pedal
• Stronger pedal pressure does not significantly change frequency
• Pump runs more frequently when clicking becomes excessive

Observed click frequency:
• Approximately every 1–1.5 seconds
• Occasionally up to twice per second

 

Awesome thank you!!