This result is happening very seldomly but I can see it on the logs. First I get a 0x0000 result and then a 0x000A result in the fds event hanlder after calling the fds_record_update function. fds_record_update is returning FDS_SUCCESS.
The event value on the fds event handler on both result values is 0x02 (FDS_EVT_UPDATE).
FDS_ERR_NOT_FOUND seems to be the corresponding code for a 0x000A result.
These are the fds_stats just before calling fds_record_update
pages_available:3 open_records:0 valid_records:5 dirty_records:33 words_reserved:29
words_used:983 largest_contig:639 freeable_words:911 corruption:0
It seem not to affect the functioning or the storage but it may be an issue an we are close to final production.
Thanks for your help!