Time series panel can look empty when “Connect null values = Threshold” is smaller than datapoint interval (tooltip still shows values)

### What happened? In a Time series panel, if I set Connect null values to Threshold = 1m, but my series has datapoints roughly every ~2 minutes, the panel becomes visually misleading: the graph looks almost empty (no visible line), even though datapoints exist — confirmed by the tooltip, which still shows the correct values when hovering near timestamps. If I increase the threshold to a value greater than the datapoint interval (e.g. 3m+), the series becomes visible again. This is confusing because it looks like Grafana is missing/losing data, while it’s actually just not rendering anything visible. ### What did you expect to happen? Tooltip behavior should be consistent with what is actually rendered (currently tooltip shows values but the plot appears empty). ### Did this work before? yes, with grafana 10.4.9. ### How do we reproduce it? Create a Time series panel. Use a query/data source that returns datapoints every ~2 minutes (fixed interval). Panel options: - Draw style: Lines - Show points: Never - Disconnect values: Threshold - Threshold: >1m Observe: the series is not visibly drawn (panel looks empty/near empty), but hovering shows tooltip values. Change threshold to 3m (or anything > 2m) → the series becomes visible again. ### Is the bug inside a dashboard panel? _No response_ ### Environment (with versions)? Grafana: 12.2.1, also tried with grafana 12.3.1 OS: Browser: ### Grafana platform? None ### Datasource(s)? _No response_