According to the Pravda article, the F-22 Raptor was developed by three US defense contractors: Lockheed Martin, Boeing, and General Dynamics.

The US Air Force is offended by the behavior of Russian "invisible aircraft"
Pravda | Nov 21, 2017
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[snip, via Google Translate]

The movements of Russian Su-30S and Su-35 in the sky over Syria can not be tracked by American fighters of the 5th generation F-22 Raptor.

This was in conversation with Aviation Week, said the commander of the 95th Expeditionary Fighter Squadron of the US Air Force, based at the air base of Al-Dafra in the UAE.

An unnamed American colonel said that for US pilots, the emergence of Russian fighters alongside the US is becoming an unpleasant surprise. The more the ring around terrorists shrinks, the more often such situations happen. However, the F-22 does not have a set of sensors needed to identify the aircraft at night.

The Raptor pilots encountered some other inconveniences. For example, F-22 is deprived of the opportunity to exchange data through the tactical system Link 16. Therefore, pilots have to describe the radio "what they see." Another problem is the absence of a helmet-mounted target designation system.