Starlink is the weak link here. The US military have access to their own satellite network but obviously won't share that with Ukraine, hence the relative ease of jamming in this case. Russian tech being able to jam civilian satellites isn't noteworthy.
Please do provide sources that Starklink is used for targeting weapons. I'd love to see those. Last I saw, it's widely admitted now that western "contractors" are responsible for operating western guided weapons, meaning that they are using US satellite network. Also, not sure why you'd think that if Starlink can be jammed, then US military satellites wouldn't be jammed the same way.
If you work on your reading comprehension, you'll see that nowhere does it say that Starlink is used for targeting. It's used for communication and that's being disrupted along with targeting systems which have fuck all to do with Starlink.