Helpers without context fail to render correctly

[kt12359]

Hi,

I am debugging an issue when trying to use a named variable and a custom helper without a supplemental json context in the sub-context of a #with block.

{{#with ($timeBetween ($now) "2024-03-05 08:00:00") as |days|~}}
  There are {{days}} between {{$now}} and 2024-03-05.
{{/with}} 

Is rendered as:
There are 6 between and 2024-03-05.

I stepped through the code in a debugger and can confirm that the handlebars library isn't making a second call to the $now helper function. However, if I supply some fake context:

{{#with ($timeBetween ($now) "2024-03-05 08:00:00") as |days|~}}
  There are {{days}} between {{$now what}} and 2024-03-05.
{{/with}} 

... it renders correctly. This also works:
{{#with ($timeBetween ($now) "2024-03-05 08:00:00") as |days|~}} There are {{days}} between {{#$now}}{{/$now}} and 2024-03-05. {{/with}}

But it does seem like this is a bug, because the method call without any arguments should still be recognized.

Thank you!