Yes, Zelensky is doing this because the US is sending money and guns to Israel instead of Ukraine. But Ukraine has already, since 2022, had diplomatic problems with Israel.
In November 2022, Ukraine supported a UN resolution that asked the International Court of Justice to investigate Israel's "prolonged occupation, settlement and annexation of Palestinian territory". In response, Israel summoned and admonished Ukrainian ambassador. Shortly after, in "an apparent act of retaliation", Israel did not vote for a UN resolution calling on Russia to pay reparations for invading Ukraine.
During the 2023 Israel–Hamas war, Ukraine's Foreign Ministry condemned attacks on Palestinian civilians in Gaza and supported a two-state solution to the conflict. More than 300 Ukrainian scholars, activists and artists expressed solidarity with Palestinians in an open letter. Most of the Ukrainian community in Gaza was forced to flee the country because of the war.
On 2 June 2024, Zelensky reiterated Ukraine's support for a two-state solution. He remarked that, while Ukraine has supported Israel's right for self-defence against Hamas during the attacks in October 2023, during the humanitarian crisis Ukraine said that is ready to help Gaza humanitarianly and it "will do everything so that Israel stops and civilians do not suffer."
Yes, Zelensky is doing this because the US is sending money and guns to Israel instead of Ukraine. But Ukraine has already, since 2022, had diplomatic problems with Israel.