tax credit run on and job ending

Hi

If someone could help.
We are claiming tax credits . We get child tax credit and disability elements for both of the children. My partner worked 24 hours until 07/05/2018. I claim Carers allowance. We seldom got the working tax credit due to income delclard lalast tax year.

I phoned the tax credit dept to inform them . They Saud we would get a 4week run on of working tax credit until 4th June. Then child tax credit only if our situation didn't change.
My partner has also apply for carers allowance.
Q1.DO we need to apply for tax credit again on the 4 th June or is it done automatically?
We are going live to universal credits on 20th June in our area.
I'm hoping not to apply for universal credit as we would be disadvantaged I've been advised.

If my partner finds a job after 20june will this trigger universal credit application.

Please advise.