How to solve the problem with the exchange between Bitrix and UT?

Question

1C-Bitrix

Earlier improvements were made on the exchange, namely the deactivation of goods that are not on the balance and the reverse activation when they appear on the balance during the exchange. There is an error in the exchange. As a result, the goods are deactivated, but not activated when they appear on the balance during the exchange.

Answer 1

Unfortunately, full-time telepaths are now on vacation, so leading questions:
1. Is the exchange typical or self-written?
2. In addition to activating and deactivating, were there any other improvements to the exchange?
3. After that, a failure began to appear - did you update the kernel, changed the server configuration, did something finalize?