Sounds like it might have been a Patriots-in-Iraq kind of situation. There was an immediate need, there was an unfinished weapon still in development that fit the bill, it was pushed out while skipping late-stage work to get it available as soon as possible, and it had problems.
“They raced and did it as fast as they could,” LaPlante continued in his remarks yesterday. He added that U.S. authorities truncated typical testing requirements to help speed the weapon system in question to Ukraine. Previous reporting has said that months of testing were still required before the GLSDBs could go to Ukraine. The weapons are not currently in U.S. military service. “We said, look, just test for safety. Otherwise the operational testing will be non-cooperative with the Russians,” according to LaPlante. “And so then we sent it to Ukrainians. It didn’t work.”
That does limit inexpensive options that can reach further than GMLRS. ATACMS can do it, but it's only available in limited numbers and is costly.
It sounds like the ER GMLRS might be further along, but it's only starting production, so there aren't large stockpiles to draw from.