Span with 1 rem font size added to text after deletion

Checklist

• I've looked at the documentation to make sure the behavior isn't documented and expected.
• I'm sure this is an issue with Summernote, not with my app or other dependencies (Angular, Cordova, React, etc.).
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Steps to reproduce

1. Open a Summernote editor. Font size drop-down has 16 selected by default.
2. Focus in the editor, hit enter a couple of times, then type a sentence of text (line 1). Hit enter and type another line of text (line 2), then hit enter a couple more times before entering another line of text, then a few more lines (lines 3-5).
3. Check Code View, confirm there are no span tags around any of the text entered.
4. Move the caret to the start of the editor. Delete the empty lines to move the text up to the start.
5. Font size drop-down now has "1" selected. Check Code View and a span with font-size:1rem has been added around the content of the first line (1) of text.
6. Move the caret to the empty space between lines 2 and 3 of text. Delete the empty space. A span with font-size:1rem is now added to the line (3) that has been moved up.
7. Select line (4), delete it, and delete the empty line. Line (5) now has the span added.

Expected behavior

A span tag with font-size:1rem should not be added around following text when lines are deleted.

Current behavior

A span tag with font-size:1rem is added on following text when lines are deleted.

Minimal example reproducing the issue

No response

Environment

• Summernote version: 0.91 and 0.8.18
• Browser (with version): Chrome 147.0.7727.138 (Official Build) (64-bit)
• OS/Platform (with version): MS Windows 11 Pro 10.0.26200 build 26200