There is one big difference. In the case of Ukraine, there is one side who is wrong and the other right. In the case of Israel, both sides are wrong. Helping Ukraine is in the US's interest. Helping Israel is out of obligation and not in US interest.

I can’t see any real difference in the struggles of the Ukrainian people to hold onto their land versus the struggles of the Palestinians to hold onto theirs. The US has chosen sides in both those battles based entirely on what helps the US.