No. There are no US Military personnel or contractors operating weapons in Ukraine. That is Russian propaganda. We have committed but not fully delivered $141 billion in aid to Ukraine since they were invaded in February 2022 and continuing through FY 24. The EU and EU nations have contributed just under $150 billion to Ukraine over the same period.
If Russia is dissatisfied with things as they now are, they can simply withdraw from Ukraine (including Crimea) which they illegally invaded and seized - do recall the Russians GUARANTEED Ukrainian borders along with us and the UK in the 1994 Budapest Memorandum in order to get Ukraine to give its nukes to Russia. Russians might also consider withdrawing from Abkhazia and South Ossetia in Georgia, which they seized and hold illegally by force of arms.
The Russians maintain a constant stream of misinformation by use of state media, internet trolling, internet clickbait, feeding Bravo Sierra to friendly Western talking heads, and by fooling useful idiots in many countries to further their lies.
Not a fan.