Undefined errors during selection

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Prerequisites

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Description

I'm incorporating MathLive and have run into a reproducible issue where I get a bunch of undefined errors. My input box has a few helpful keys to insert characters which might be contributing but I can't tell. The output LaTeX of the input box at the time is \left({\frac {5}{3}}\right)^4.

Steps to Reproduce

I installed MathLive via NPM. I import the mathlive JS file using a Webpack build and manually copied the CSS and fonts into our project.

In my input box I manually typed "5", "/", "3", then selected everything and pressed a button in our UI that runs perform(['insert', '\\left({#0}\\right)', { focus: true, feedback: true }]) to wrap parenthesis around the selection. After that I press another UI button that runs perform(['insert', '^{#?}', { focus: true, feedback: true }]) to add an exponent placeholder (which I fill in with the 4).

I then started to click around in the input box, selecting and deselecting things somewhat rapidly (mostly as an idle action while I was thinking) and the errors started to appear.

Actual behavior

I get a lot of errors and the input box no longer responds to input.

 [Show/hide message details.] TypeError: e is undefined[Learn More]
mathlive.js:1
../../node_modules/mathlive/dist/mathlive.js/</</s</k.prototype._pathFromPoint/n<
mathlive.js:1
<anonymous> self-hosted:988:17 ../../node_modules/mathlive/dist/mathlive.js/</</r</s.prototype.filter
mathlive.js:1
../../node_modules/mathlive/dist/mathlive.js/</</s</k.prototype._pathFromPoint
mathlive.js:1
i
mathlive.js:1
[Show/hide message details.] TypeError: this.mathlist.anchor(...) is undefined[Learn More] mathlive.js:1
../../node_modules/mathlive/dist/mathlive.js/</</s</k.prototype._render
mathlive.js:1
../../node_modules/mathlive/dist/mathlive.js/</</s</k.prototype._onFocus
mathlive.js:1
<anonymous> self-hosted:984:17 u
mathlive.js:1
../../node_modules/mathlive/dist/mathlive.js/</</s</k.prototype._onPointerDown
mathlive.js:1
<anonymous> self-hosted:986:17 

Expected Behavior

I would expect no errors.

Environment

Operating System Windows 10 Pro

Browser Firefox Developer Edition

URL N/A