You actually sent the output showing /var/tmp, not /var.
These two are mounted on different partitions.
You can see what files you have on /var. Some of them are not subject of
deletion when 'request system storage cleanup' is run. But maybe you
don't need them and you can safely delete them.
If you don't have any other files to delete, then you will either have
to live with the alarm or increase the threshold.
There is no problem if you have this alarm if you don't end up in having
no disk space at all.