@robert8103 I don’t believe that triggering of alerts on a per-series basis is currently supported. This comment by Torkel indicates that it wasn’t back in 2017, and the corresponding Github issue is still open (with more than a couple of interested parties).
Unless my understanding of the implementation is outdated, I’m actually surprised to hear that you’re getting alerts for multiple series at all. Normally what happens is that an alert is triggered as soon as one series crosses the threshold, and while that alert is active no others are triggered (even if other series also cross the threshold). I think the comments in the links probably explain this even better.