Global plug-in variables ("$__zbx") stop working when using more than one Function

[isaqueprofeta]

Describe the bug
On the Functions scope, global plug-in variables ("$__zbx") stop working when using more than one Function. If you add a aggregatedBy() or other functions, Grafana will output a string of "$__zbx" instead of the value.

Expected behavior
When using setAlias or replaceAlias with "$__zbx" I want to see the value of the Global variable.

Screenshots

Only using setAlias works:

When adding another Aggregation function to the stack, it stops working:

Network data

Software versions

Used https://play.grafana-zabbix.org/ for tests.

[isaqueprofeta]

Pinging @yesoreyeram since the pipeline failed on github for the "OSS Big Tent team project"