Time machine created a new backup file

MCH has been working properly over 8 months.
3 days ago time machine started a new backup fine.
So, I only have a backup 3 days old, I can not go back over 3 days.
The mirror copy is still in the MCH since I can see it via Finder.
How can make Time Machine to go back to the old file.
Thanks for your help
JP

I have same problem since I have the home due they create 13 different back ups and I can’t not access the older one!!