Thank you all for the answers!
Autoformatting was configured by the integrator, it seems, for Binotel.
AlfaSMS technical support confirmed that the "380" format is suitable, "+" is not needed. Made appropriate changes.
https://ceylon.crm-onebox.com/app/contact/settings/phone_auto_format/Now all messages with the status "waiting to be sent" have been sent.
How to filter customers who did not receive SMS and the process ended with "error" status?
I want to send them a message again.