I found those two event interesting.
https://www.deccanherald.com/content/613279/su-30-mki-goes-missing.html
And this
https://sputniknews.com/middleeast/201805031064108502-russia-su30-syria-crash/
The First one crash in India close to the Chinese border. The other one in the Mediterranean right after take off.
In both case both the four pilot where unable to eject. 2 pilot per plane.
I find this quite odd. Is it possible that it is not the Russian who are using electronic warfare to keep the US from flying their plane but an other actor?