Sender not found. periodic error

For example here https://rivcont.info/3649494/ There was an error https://take.ms/bxlYI , but then after 5-7 minutes everything is carried out. We wrote to the NP, they said that they fixed it, but the error remained. Here's what they advised: The problem with duplication of contact details identifiers has been resolved, it is recommended to update the counterparty and contact details identifier: https://developers.novaposhta.ua/view/model/a28f4b04-8512-11ec-8ced-005056b2dbe1/method/a37a06df-8512-11ec-8ced-005056b2dbe1 https://developers.novaposhta.ua/view/model/a28f4b04-8512-11ec-8ced-005056b2dbe1/method/a3575a67-8512-11ec-8ced-005056b2dbe1 Maybe directories slow down or something else, but such an error occurs almost every day. Please see what the problem is and if so fix it.