Paragraph Tags removed when contents are only a shortcode

Question

I'm developing a plugin that given a shortcode with attributes will scan a json file and return the appropriate data etc.

Given code like this:

<!-- wp:paragraph -->
<p>[environ data="day_max" format="long"]</p>
<!-- /wp:paragraph -->

<!-- wp:paragraph -->
<p>[environ data="day_min"]</p>
<!-- /wp:paragraph -->

Data is being returned like

9.82°C at 12:49:59 AM 9.82°C

without the paragraphs and bunched together. If I add any leading text the problem vanishes (see below). If I place short codes within table cells it vanishes. The issue only presents itself if the short code is alone in a paragraph.

<!-- wp:paragraph -->
<p>Test [environ data="day_max" format="long"]</p>
<!-- /wp:paragraph -->

returns

<p>Test 9.82°C at 12:49:59 AM</p>

I've looked at Remove empty p-Tags in Shortcode content before non p-Tags and similar posts but they don't seem to address this issue.

My code is a add_shortcode('environ', array(&$byteenviron ,'byteenviron_display_handler')); function call to byteenviron_display_handler which processes the attributes and returns a string.