fetching an acpu_variable leads to "false" - although data is there

[AloisKlingler]

hi,

I am using php-7.3 with php-apcu 5.1.17 (both from raspbian 10.13) in several php scripts.

I have mainly stored arrays in acpu-variables.
now on a pre-elementary check I noticed, that the variables after apcu_fetch are "false" - and most astonishing associative references to the arrays work.

e.g.:
$froniusvalues = apcu_fetch('froniusvalues');
shows me on "var_dump($froniusvalues)" only "false"
and
if (is_array($froniusvalues)) {
fails, but a line below
$froniusvalues["P_PV"];

works correctly.

any idea if I am doing something wrong, or what's strange there?

Thank you. :-)

BR
Alois