New job offer same trust different payband part time on Tier 2 visa

Hello,

I am on Tier 2 visa/health and care visa. Working as Band 5 NHS Nurse full time. I have a job offer as Band 6 Research nurse from same trust /employer but part time and fixed term 18.8 hrs.
Can I accept.the job offer?
My line manager agreed to second me so the other 18.8 hrs, I will still do it in ICU as Band 5.
Is this possible or allowed considering different pay bands and also my immigration status Tier 2?
If so, is there a need for new COS or visa application.I am eligible for ILR application next yeat already.

Thanks in advance. HR/Recruitment can not answer my queries so was hoping someone could as I am very keen to accep the job.

refer to the gov website https://www.gov.uk/health-care-worker-v ... second-job

You can do additional paid work on this visa as long as you’re still doing the job you’re being sponsored for. You can work up to 20 hours a week (but see NOTE below) in a job that’s either
in the same occupation code and at the same level as your main job or in a shortage occupation.

The SOC code for nurses is 2231 and it is a shortage occupation at the present time.

You don't need a new CoS and don't need to inform the Home Office before taking the extra work.
NOTE
Due to coronavirus (COVID-19), there’s currently no limit on the number of hours you can work or volunteer if you have a second job as an NHS doctor, nurse or paramedic.