Hello Dannison!
Thanks for your answer!
In fact, the click happened 4 hours before the system tried to send offline conversions. I'm trying other conversions that happened shortly after and are still causing the same error.
I don't think the problem is the window between click and conversion, must be something else.
The gclid EAIaIQobChMI1-jN-LDV4gIV3oyyCh14pw3CEAEYASAAEgJJ2PD_BwE for example had the clicked event in 2019-07-20 20:11:17. As showed in the header of the SOAP above, the first time I tried to send conversions was at "Date: Sun, 21 Jul 2019 01:00:02 GMT" 4 hours later, exactly the numbers of hours Google expect to wait for receive conversions.
I have more 15 gclids to send that happaned between saturday and today. I'm trying to send one by one, and I still got the same problem.
Could it be something else?