I ran into this yesterday. It turns out that when I created my mySQL database back in 2019 I used INT for the pk value. The maximum value that an INT can be in mySQL is 2147483647. pk values went above that number yesterday. I changed my database to BIGINT for the pk value and everything is working normal again.
I am not familiar with the OpenALPR LPR Downloader implementation of the pk value, but this might the issue.
edit: Add more context
The data was being downloaded properly it just couldn't be imported into the database because of the pk value being higher than 2147483647. Due to the automated nature of my setup I was not seeing any error messages until I started trying to import by hand. With some googling of error messages I figured out the issue.
With pk as a BIGINT I should be good until pk gets above 9223372036854775808.
Code:
[LPR]>select pk, epoch_time_start from Plates where pk >= '2147478437' order by pk limit 2;
+------------+---------------------+
| pk | epoch_time_start |
+------------+---------------------+
| 2147478437 | 2022-07-06 11:15:50 |
| 2147492777 | 2022-07-06 11:20:23 |
+------------+---------------------+
In the almost 5 minutes between these entries the pk value went above the max value for an INT. Times shown are mountain time.