loyalty discount sometimes not reflected in total

[JohnnyPatrol]

Hi,

 

I am using Presta 1.5.4.1 and the Loyalty module version 1.8.

I know this is not the recent version, but upgrading presta always leads to loads of trouble, so I would like to avoid it unless there is a real benefit.

 

I believe my problem is best described by these two pictures:

 

As you can see in one picture, the discount is missing in the total. This only happens occasionally.

 

Is this fixed in a newer version or do you have any idea?

 

Thanks a lot