  We have investigated temporal fluctuation of superconducting qubits via the
time-resolved measurement for an IBM Quantum system. We found that the qubit
error rate abruptly changes during specific time intervals. Each high error
state persists for several tens of seconds, and exhibits an on-off behavior.
The observed temporal instability can be attributed to qubit transitions
induced by a measurement stimulus. Resonant transition between fluctuating
dressed states of the qubits coupled with high-frequency resonators can be
responsible for the error-rate change.
