[iOS][Safari] The window slows down after uploading the recorded videos from the Upload menu

[Softvision-RemusDranca]

[Affected Versions]:

• Safari 14

[Affected Platforms]:

• Iphone SE 14.4

[Prerequisites]:

• Have a room opened on "https://hubs.mozilla.com/" website.

[Steps to reproduce]:

1. Tap on the "Place" button from the menu bar.
2. Tap the "Upload" button from the prompt displayed.
3. Tap the "Attach" button.
4. Select the "Take Photo or Video" option.
5. Record the video and tap the "Use Video" button.
6. Interact with the window and observe the behavior.

[Expected results]:

• The window is responsive.

[Actual results]:

• The window is frozen.

[Notes]:

• I was unable to refresh the page after reproducing the issue.
• I was not able to reproduce the issue when taking a photo.
• Attached is a screen recording of the issue: link.

┆Issue is synchronized with this Jira Task

[takahirox]

Not frozen but the window becomes very slow after uploading video on my iPhoneX (iOS 15) Safari

[Softvision-RemusDranca]

@takahirox I have the same behavior, now and the window did not freeze but I do see that performance issue. Iphone SE2 (iOS 15) Safari. I'll update the title to reflect the current behavior.