[Grid] .MuiGrid-grid-md class does not load when the page is loaded at xs width

• This is not a v0.x issue.
• I have searched the issues of this repository and believe that this is not a duplicate.

Expected Behavior 🤔

Grid should be responsive even when the page is loaded as xs width.

Current Behavior 😯

Grid is not responsive.

Steps to Reproduce 🕹

The bug is reproducible here: http://ec2-18-217-230-111.us-east-2.compute.amazonaws.com/diagnoses/Ondine’s curse (It is a live (changing, in development) site, but I’ll try to keep it in the state so the bug is reproducible for some time.)

1. Shrink the page to xs size (<600px width).
2. Click on the “Dark Diagnosis” in the header. (This will go to another route, thus unmounting the components from the current route.)
3. Widen the page above xs size (>600px width).
4. Click on some image (for example the one that was open initially), thus going to the single image route. (If you clicked on the image that was open in the beginning you will go to the initial route).

The image and description will stay at 100% width. The image and description should shrink to 50% width each, and they should fit in the same row. Grid’s sm class was not applied to the component.

The following code describes the mentioned components on the above given website:

        <Grid container>
            <Grid item xs={12} sm={6}>
                <img src={diagnosisData.imageUrl} width='100%' height='100%' style={{borderRadius: '5%'}}/>
            </Grid>
            <Grid item xs={12} sm={6}>
                {descriptionComponent}
            </Grid>
        </Grid>

Context 🔦

The bug does not occur always. After it occurs, changing the width by 1px the .MuiGrid-grid-sm class gets applied to the elements correctly and the elements shrink.

Your Environment 🌎

Tech	Version
Material-UI	v4.2.0
React	16.8.6
Browser	Chrome 75.0
TypeScript	No

(Couldn’t reproduce in FF)

[croraf]

I’ve tested a bit. The issue happens until v81, and does not happen at v83. So it is confirmed that it’s been fixed in Chrome somewhere in that period.

[croraf]

@mbrookes It would be at least good that someone else confirms that this doesn’t appear any more on latest Chrome, as the issue is not of consistent nature.