How to reset the infoblock cache through an event?

Question

1C-Bitrix

Good day!
The essence of the problem: at the moment of changing the IB element (infoblock), you need to reset the cache of another IB.
I make an onAfterIBlockElementUpdate event and try to flush the cache But nothing comes out, dumping what it returns is null. How can I reset the cache of the infoblock \CIBlock::clearIblockTagCache(44)