multipart template does not keep variables

Describe the Bug

when you create a template from xxx template files, a variable created in one part of it is not usable in the others

Expected Behavior

template('file1','file2','file3');

if file1 define variable="ok"

in file 3 you cannot use the variable.

Steps to Reproduce

Create a template

file1 <% myvar='ok' %>

file2 xwhaterver

file3 <%= myvar %>

template('file1','file2','file3') =>> fail

Environment

• Version puppet 7
• Platform deban12