An argument can be logically valid and still untrue.
Only if at least one premise is untrue. If however the premises are true and the argument is logically valid, the conclusion is also true.
Interesting to note that the opposite is not necessarily true - flawed premises and/or a flawed argument do not imply an untrue conclusion. Easy to show with an example:
P1 - whales are fish (wrong - they’re mammals)
P2 - fish live only in the sea (wrong - freshwater fish exist)
C - whales live only in the sea (true conclusion from bullshit premises)
…which leads to the “fallacy of fallacy” - "the proposition is backed up by a fallacious argument, thus it is false is on itself fallacious.