The USA has severed a key intelligence line for Ukraine, stopping the transfer of data for targeting HIMARS. The decision took effect at 2:00 PM Kyiv time after the Trump administration froze military aid.
Archived version: https://archive.is/newest/https://unn.ua/en/news/the-usa-has-effectively-disconnected-himars-for-ukraine-halting-the-exchange-of-intelligence-data
Disclaimer: The article linked is from a single source with a single perspective. Make sure to cross-check information against multiple sources to get a comprehensive view on the situation.
A note: this doesn’t mean Ukraine’s HIMARS systems can’t fire. The difficulty is in identifying the coordinates of targets accurately, not in giving the missile instructions