Time Machine making full backups instead of incremental after macOS Tahoe 26.1 upgrade

l seems there is a problem with Time Machine since I upgraded to Tahoe 26.1.

I have a MacBook Air with a 500GB Disk, 277GB Available.

I use Time Machine to make hourly back-ups on an external bakcup drive in my Wifi Network.

Since the upgrade it takes about 4 hours to make the backup. (with the power connected to the Macbook).

When I just checked the progress of Time Machine, it says that it completed 33% of the back up and that it copied 110 GB and that it needed another 4 hours. Since yesterday, it has eaten about 700GB of my external drive.

I checked the backups and I saw that it has made backups overnight at 1, 4 and 8 AM (approximately).

It seems that Time Machine is now not making incremental backups but full backups.

What can be done about it.

[Re-Titled by Moderator]

Original Title: Time Machine making full