[Koha] Problems with circulation history

[vanda koha]

Hi everybody!

We are using koha version  16.11.04.
I´ve recently detected a problem with circulation history. The program
cheks out and cheks in all items quite well, but it frequently does not
keep track of all the loans. After checking in a book when I run the report
to see what was checked in the book does not appear in the results and when
I check the patron circulation history it shows no loans (It shows: "This
patron has no circulation history"). When we look in to the checkout
history of the item it says the book has never been checked out before.
It is as if the item had never been checked out. To make it even more
strange let me tell you that this happens in a regular basis, but not
everytime. I was not able to understand why this only happens every now and
then. What do you think might be the problem? How can we solve it?
Has it ever happened to anyone of you?
Any help would be very welcomed.

Thanks

Vanda