Change from tax credit to universal credit

[NoMatterswhat]

I claim working and child tax credit. I tried to log on line to tax credit payments and it kept redirecting me to universal credit website. When I rang they said there were no further payments scheduled and to try universal
Credit and couldn't tell me much more.
Does any one know why this might have happened? I usually get my payments every week. I have had nothing to trigger a change to universal credit and can they do this without letting me know

Bump

It does seem a bit strange if you are absolutely sure you haven't had a change in circumstances over the last few months, Have you been furloughed? And did you just not receive your payment.

Has your income changed as it is review time?
Ir it could be natural migration but I thought they had put that on hold due to lockdown.

You should receive a letter to state why its stopped. I would if you can as once you claim UC there is no going back.

Thanks for replies. I have not been furloughed and no change in income I have no idea why. Tax credits in the end just said he would put a note on asking for next payment to be reviewed.