Google Apps + Yandex mail = no spam?

An appeal to those who use a similar bunch.

(incoming gmail apps -> forwarding to yandex mail to clear spam -> back to gmail and scattered to recipients)

We have mail on Google Apps, many different emails with different domains. In the mx settings of the hoster google addresses are registered according to the instructions. (total of three servers 1, 2, 3 levels).

Previously, all mail flowed to 1 of my administrator accounts, where it was distributed to recipients through filters. But a year later, the amount of spam exceeded 50 letters per minute, I began to look for an opportunity to get rid of it at least somehow. Plus, often the necessary letters fell into the spam daddy (mine), and the recipients asked me to see the new mail in spam.

Did the following:

All mail flows to the “nospam” account on gmail apps, after which it is immediately transferred through gmail filters to Yandex mail, where it is filtered from Spam and is already forwarded to my administrator gmail account and then distributed to the right recipients through filters.

The first week everything worked like top. Then they began to notice that letters were disappearing.
Fortunately, there is a nospam account where you could find missing incoming letters. Later it turned out that Yandex had some kind of problem with the mail and for some time even the search in the mail did not work (this Yandex JV was unsubscribed).

Today I began to check mail in nospam - I was horrified, at the end of May a large number of letters got stuck.
Some did not reach Yandex (remained in nospam), some did not leave Yandex back to gmail.

It is not clear what the problem is, in Yandex, in the hoster, in Google, or in Google filters.

Maybe someone faced the same problems? Or is there another way to get rid of spam? :) Yandex spam filters are better than google, but it would seem like a good idea to make a double barrier spoiled by such problems.