Thanks so much for your help Clarice.
I was using 2.0.3 because that is the one that was available in google play, I deleted it and downloaded 2.0.5 from github repository.
I have deleted the opendatakit folder and apps from my handset and installed 2.0.5 of services, tables and app designer too. I have made a fresh instalation of your example and unfortunatelly I get the same error. I cannot understand why it works for you and not for me but it is driving me crazy.
Please find attached the config folder. I have included the log file too. I have only uploaded your xlsx file to the xlsx converter, have not changed anything and throws the same error as I had with mine when I push it to the handset and run survey.
It works perfectly in the app designer emulator.
config.zip (971.9 KB)
Thanks again for your help!!