For the last few weeks wikidata has included dispatch lag in maxlag.
The tracked lag can be seen @ https://grafana.wikimedia.org/dashboard/db/wikidata-dispatch?refresh=1m&panelId=22&fullscreen&orgId=1&from=now-7d&to=now
Some bots & scripts are not passing sensible values to maxlag, either NULL or a very large number.
This ticket tracks the contacting of those people in sub tickets with NDA access (no idea if including UAs etc need to be hidden).
A hive query that can be used to get the information needed to follow up here (once you modify the dates) can be found below:
SELECT COUNT(*) AS requests, useragent, params["maxlag"] AS maxlag, array_contains(errorcodes, "maxlag") AS hitMaxLagError FROM wmf_raw.apiaction WHERE wiki = "wikidatawiki" AND params["action"] RLIKE '^wbl?(create|edit|set|add|remove|link|merge)' AND (array_contains(errorcodes, "maxlag") OR haderror = 0) AND useragent != '127.0.0.1' AND YEAR = 2018 AND MONTH = 07 AND DAY = 15 GROUP BY useragent, params["maxlag"], array_contains(errorcodes, "maxlag") ORDER BY requests DESC LIMIT 1000;