Unsaved log files even with "save incomplete results" enabled

URL of experiment: PTC [PsychoPy]

Description of the problem:
As the title suggests, we are having trouble viewing some datasets that aren’t saved.
We use Prolific to recruit subjects, and the experiment must be completed on Pavlovia.
Data files are set up in a way to have the subject’s ID as part of the file name. However, even though some participants claim to have completed the experiment, we cannot locate any log files associated with their IDs.
So the question is: under what conditions could a participant participate in a Pavlovia experiment with “save incomplete results” enabled, but we still don’t get anything from that particular subject?

Hi @Amir, I saw that you redirect participants to a google form after the experiment. Did you verify that they completed this part so you can be sure that they actually took part to the end and its definetely a problem with pavlovia?

Hi @ajus , we redirected incomplete attempts to a google form that contained instructions on withdrawing from the experiment. Because they didn’t have to submit any responses on the form itself, nothing was recorded there.
On the other hand, we used a google script at the beginning of the experiment (before redirecting to Pavlovia) for conditional counterbalancing. According to the spreadsheet that was attached to the script, they all loaded the script link which would have automatically redirected them to Pavlovia (as it did for the majority of the participants)

Ah, ok. So you know, that these participants who claim to have completed the experiment definitely started the experiment from the google spreadsheet, right? And they also provided the correct completion code after a reasonable amount of time?

We know that they clicked on the script link, which would’ve automatically redirected them to the experiment.
Some did not provide the completion code, and we cannot find any datasets associated with them; which is why we’re curious to know under what conditions can the log files not be saved, even if they partially ran the experiment (the original question) ?