Unable to make iCloud full backup

Hello,

I have a problem with making an iCloud backup of my iPhone. I store there my whole Photos library and up to this time my iPhone backup. But I made a clear installation of my iPhone (backup on my mac, then restored it from the backup). When I turned on iCloud backup again it shows me, that I have insufficient storage plan.

In fact, I have 50GB plan and total space that I need is around 46 GB.

Can sb help me, please?