Mediawiki Scribunto: <div style=> renders the entire variable it is a part of nil

The wiki page in question. The presence of <div style=> inside a Lua template's variable (content or args[1]) renders the entire variable nil.

Template and module used:

• Module:BubbleBox/hex: A Lua module to sandwich content/args[1] between a preset div class and style.
  • Template:BubbleBox/hex: Mediawiki template that invokes the aforementioned Module.

Screenshot of expected vs. result

• Expected (how it should look): The image and caption shows and centered properly.
• Result: Said <div style=> makes the entire args[1] variable nil.

Classical. = in a numbered template parameter makes it technically named: {{t|a=b}} will not be treated as {{t|1=a=b}}.

You should either replace = with {{=}}:

{{BubbleBox/hex
|classes=tagInfobox
|styles=width: 350px; padding: 8px; float: right;
|{{InfoboxTitle/hex|TEST}}
<div style{{=}}"text-align: center;">
[[File:Inkipedia Logo 2022 - S3.svg]]
Insert caption here
</div>
{{{!}}
{{InfoboxProperty/hex|TEST|text 1}}
{{InfoboxProperty/hex|TEST2|text 2}}
{{InfoboxProperty/hex|TEST333333|text 3 loong}}
{{!}}}
}}

or explicitly state the argument name:

{{BubbleBox/hex
|classes=tagInfobox
|styles=width: 350px; padding: 8px; float: right;
|1={{InfoboxTitle/hex|TEST}}
<div style="text-align: center;">
[[File:Inkipedia Logo 2022 - S3.svg]]
Insert caption here
</div>
{{{!}}
{{InfoboxProperty/hex|TEST|text 1}}
{{InfoboxProperty/hex|TEST2|text 2}}
{{InfoboxProperty/hex|TEST333333|text 3 loong}}
{{!}}}
}}