Grafana panels blinking between “data” and “No data” on refresh (Loki + JSON logs) — Geomap/Time series/Table

Grafana
,
1 
Hi community,
I’m using Grafana v12.3.0 with Loki as datasource. Multiple panels keep blinking/flipping on auto-refresh: one refresh shows correct data, the next shows “No data”, then it comes back again. This repeats continuously. It happens across several panel types, including Geomap, Time series, and Table.

What I mean by “blinking”
	•	Dashboard auto-refresh (e.g., 5s / 10s)
	•	Panel alternates between:
	•	✅ expected results
	•	❌ “No data”
	•	Then returns to expected results again, repeatedly.

Data source and logs
	•	Datasource: Loki
	•	Logs are JSON lines ingested into Loki (Promtail)
	•	Labels are stable and present (example):
job="project", log_type="traps" (plus other labels like type/layer/trapId)

Proof the data exists (Loki API returns data consistently)

When I query Loki directly via API, it returns results reliably during the same time range where Grafana UI sometimes shows “No data”:

curl -sG "http://127.0.0.1:3100/loki/api/v1/query_range" \
  --data-urlencode 'query={job="project",log_type="traps"} | json | __error_=""' \
  --data-urlencode "start=${START_NS}" \
  --data-urlencode "end=${NOW_NS}" \
  --data-urlencode "limit=50"

So Loki ingestion appears OK; the instability seems to be in Grafana query/panel processing.

Example log structure (sanitized — no identifying values)

{
  "t": 1234567890,
  "type": "trap",
  "ip": "REDACTED",
  "trapId": "GW_REQ",
  "reason": "rid=REDACTED",
  "layer": "gateway",
  "route": "GET /something",
  "ua": "REDACTED",
  "geo_country": "SomeCountry",
  "geo_country_code": "XX",
  "geo_city": "SomeCity",
  "geo_lat": 0,
  "geo_lon": 0,
  "dst_lat": 0,
  "dst_lon": 0
}

Basic Loki query used by multiple panels:

{job=“engchat”,log_type=“traps”} | json | _error_=“”

Geomap panel specifics
	•	Geomap layer = Markers
	•	Location mode = Coords
	•	Uses extracted JSON fields for latitude/longitude
	•	Some markers blink more than others (not all points disappear at once)
	•	I’m using transformations like:
	•	Extract fields (JSON)
	•	Convert field type (lat/lon to number)
	•	(Optional) group/organize fields

What I’m asking

What could cause Grafana panels to alternate between valid results and “No data” on refresh, even while Loki query_range consistently returns data?

Things I’d appreciate guidance on:
	•	Known issues with Geomap + Loki + JSON + transformations
	•	Whether Query options (interval / max data points / direction / step) can cause alternating empty frames
	•	Whether reduce/transform behavior can intermittently produce “no fields” causing the panel to render as “No data”
	•	Any recommended best practices to stabilize results across refreshes

Thanks in advance.