rsync running under rsnapshot is not creating hard links, why?

I have rsnapshot taking backups for me. However, each backup is the full size of the source data. It is not making hard links and instead is making new copies of ever single (unchanged) file on every instigation. I have verified that new files are being created in each backup by checking the inode numbers against each other and also by counting hardlinks (there's none). The problem seems to be occurring at the rsync stage. rsync looks to be transferring every file at each instigation. The reason is ">f..T......", so to my understanding, it is transferring and creating a whole new file based on a differing timestamp to the backup. In fact the timestamps are significantly different, e.g. on the local system: Access: 2024-03-18 10:14:28.285098766 +0000 Modify: 2023-11-23 21:04:36.000000000 +0000 Change: 2024-03-10 21:11:26.107904822 +0000 Birth: 2023-12-02 19:22:02.022412357 +0000 and the same file on the backup: Access: 2024-03-18 10:14:29.369122130 +0000 Modify: 2024-03-18 10:14:30.609148859 +0000 Change: 2024-03-18 10:14:31.817174900 +0000 Birth: 2024-03-18 10:14:29.369122130 +0000 The upshot of this is that each backup takes forever and takes a huge amount of disk space, precisely the opposite of what I expect. I believe I can fix this by adding --time to the rsnapshot/rsync configuration to "correct" the timestamps on the backup. But that differs how it should be working "out of the box" so I'm reluctant to do it. My specific questions are: 1) Are the timestamps in the backup wrong in this context and what should they actually be? 2) What could have gone wrong here? I feel I may have missed a step in creating the first ever backup e.g. the first backup should have had --time. 3) Is adding --time to the config a bad idea, given it's not already there by default?