Why would material-ui's AppBar just break its own css on a few page reloads?

问题

I'll show you exactly what I mean here. (it's a short video demonstrating exactly how this problem is reproduced and the missing css elements)

I also have screenshots of before:

and after:

Via inspect element it's clear that important css elements just straight up disappear, and it doesn't make any sense why that would happen specifically after clicking on a link, coming back, and refreshing.

Has anyone run into a similar problem with material-ui before or think you might know why the css is breaking?

EDIT: console is logging errors only when the search bar is in the wacky position as such:

unfortunately, I'm still not quite sure what to make of it.

I'll also include my appbar component which uses @material-ui/core/styles' makeStyles CSS rendering. If you want the entire repository to play around with I can make it available as well.

import React from 'react';
import AppBar from '@material-ui/core/AppBar';
import Toolbar from '@material-ui/core/Toolbar';
import IconButton from '@material-ui/core/IconButton';
import Typography from '@material-ui/core/Typography';
import InputBase from '@material-ui/core/InputBase';
import { fade } from '@material-ui/core/styles/colorManipulator';
import { makeStyles } from '@material-ui/core/styles';
import MenuIcon from '@material-ui/icons/Menu';
import SearchIcon from '@material-ui/icons/Search';
import {connectSearchBox} from 'react-instantsearch-dom';

const useStyles = makeStyles(theme => ({
    root: {
        flexGrow: 1,
    },
    menuButton: {
        marginRight: theme.spacing(2),
    },
    title: {
        flexGrow: 1,
        display: 'none',
        [theme.breakpoints.up('sm')]: {
            display: 'block',
        },
    },
    search: {
        position: 'relative',
        borderRadius: theme.shape.borderRadius,
        backgroundColor: fade(theme.palette.common.white, 0.15),
        '&:hover': {
            backgroundColor: fade(theme.palette.common.white, 0.25),
        },
        marginLeft: 0,
        width: '100%',
        [theme.breakpoints.up('sm')]: {
            marginLeft: theme.spacing(1),
            width: 'auto',
        },
    },
    searchIcon: {
        width: theme.spacing(7),
        height: '100%',
        position: 'absolute',
        pointerEvents: 'none',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center',
    },
    inputRoot: {
        color: 'inherit',
    },
    inputInput: {
        padding: theme.spacing(1, 1, 1, 7),
        transition: theme.transitions.create('width'),
        width: '100%',
        [theme.breakpoints.up('sm')]: {
            width: 300,
            '&:focus': {
                width: 400,
            },
        },
    }
}));

function SearchBox({currentRefinement, refine}){
    const classes = useStyles();
    return(
        <InputBase
            type="search"
            value={currentRefinement}
            onChange={event => refine(event.currentTarget.value)}
            placeholder="Search by state, park name, keywords..."
            classes = {{
                root: classes.inputRoot,
                input: classes.inputInput,
            }}
        />
    )
}

const CustomSearchBox = connectSearchBox(SearchBox);

function SearchAppBar() {
    const classes = useStyles();
    return (
        <div className={classes.root}>
            <AppBar position="static" color="primary">
                <Toolbar>
                    <IconButton
                        edge="start"
                        className={classes.menuButton}
                        color="inherit"
                        aria-label="Open drawer"
                    >
                        <MenuIcon />
                    </IconButton>
                    <Typography className={classes.title} variant="h6" noWrap>
                        Title
                    </Typography>
                    <div className={classes.search}>
                        <div className={classes.searchIcon}>
                            <SearchIcon />
                        </div>
                        <CustomSearchBox/>
                    </div>
                </Toolbar>
            </AppBar>
        </div>
    );
}

export default SearchAppBar;

来源：https://stackoverflow.com/questions/56315802/why-would-material-uis-appbar-just-break-its-own-css-on-a-few-page-reloads