A guy just gained 19300 XP in about 10 minutes. Every few seconds that I refreshed he had 300-400 XP. That seems incredible and I believe he may be using a script to cheat. However I can't find a place to report the issue. Does anyone know where I can report it?
I reported a cheat in my league and Duolingo took action against the account. In my case the amount was nowhere near the level you were reporting, they were getting about 35XP/minute over an 8 hour window.
I do feel that it might be possible for Duo to be a little more proactive. They must know what XP/minute rate is possible legitimately and should then be able to look at accounts achieving more than this to monitor their behaviour.
An alternative would be to introduce a check such as CAPTCHA on accounts that are exceeding the limit. It should disrupt the script and be a warning to the cheat that Duo is looking at them.
Actually there is another problem with the Duolingo backend at the moment!!!
From the thread "Duolingo hanging": https://forum.duolingo.com/comment/35783994?comment_id=36036345
I can confirm this "checking/continue" screen hanging at the last question on an older Windows Laptop with Firefox V52.9.0esr installed.
There is a bigger issues with the XP tracking events that we as a user are getting now 3-4+ duplicates (same date+clock timestamp, 0 seconds delay) as longer as this window stays open.
We need to close this Duolingo web page as soon as the XP data was successfully written once (verifyable on the RAW button http://www.duome.eu/USERNAME) to prevent duplicates counting 3-4x our XP lessons/practice.
I submitted a bug report with the "other" category today but have not received the ticket id number yet.
Maybe it takes a while until this reply goes through all the filters / MTA negotiations....hopefully it went through.