RHOCP 4 .13 reboot time has increased

In BMC infra, reboot of node is taking longer time since 4.12.

OCP 4.12, 4.13

Always

1. Install cluster on bare metal servers.
2. Restart node
3.

Restart of node is takin around 15 mins.

Restart of node should not take longer time.

What are you experiencing? What are you expecting to happen?
Our test automation we  executing the Master node restart via BMC for all releases. Now we have observe that Master node Restart recovery time has increased from earlier 4.12 releases i.e. 4.12.5 average restart time was 12minute 32 second. Now in 4.12.19  restart recovery time is more than 15min and out test automation hitting to the time out. 
The Master node restart recovery time should not be increased.   

Define the value or impact to you or the business
Master node restart recovery time is not possible it increase since it's have direct impact for the application vCU&vDU recovery time. 
That can effect to the end user for longer downtime in case of restart 

Where are you experiencing this behavior? What environment?
Environment be used for testing is Airframe RM20 (3+5) MNO 
The Master node restart recovery time should be more or less similar from release to release. 

When does this behavior occur? Frequency? Repeatedly? At certain times?
For the later 4.12 releases master node restart recovery time looks to be extending. 
The recovery time behavior are same in every master node start exact time could be variate about 2 minutes but overall time has increased