Steps to reproduce the issue

Install Joomla 4 on a host that requires the use of the FTP Layer.

Navigate in admin to Content -> Media

Create a folder - that works.

Thu Apr 22 17:33:57 2021 [pid 75107] CONNECT: Client "::ffff:127.0.0.1"
Thu Apr 22 17:33:57 2021 [pid 75106] [www-ftp] OK LOGIN: Client "::ffff:127.0.0.1"
Thu Apr 22 17:33:57 2021 [pid 75108] [www-ftp] OK MKDIR: Client "::ffff:127.0.0.1", "/var/www/html/images/test"
Thu Apr 22 17:33:57 2021 [pid 75108] [www-ftp] OK CHMOD: Client "::ffff:127.0.0.1", "/var/www/html/images/test 755"

Attempt to upload an image - nothing happens. Inspect the AJAX responses...

Expected result

Image uploaded and displayed in the media manager

Actual result

FTP Log:

Thu Apr 22 17:34:27 2021 [pid 75113] CONNECT: Client "::ffff:127.0.0.1"
Thu Apr 22 17:34:27 2021 [pid 75112] [www-ftp] OK LOGIN: Client "::ffff:127.0.0.1"
Thu Apr 22 17:34:27 2021 [pid 75114] [www-ftp] OK UPLOAD: Client "::ffff:127.0.0.1", "/var/www/html/images/6081b3a39eed4.png", 344680 bytes, 87633.84Kbyte/sec
Thu Apr 22 17:34:27 2021 [pid 75114] [www-ftp] OK DELETE: Client "::ffff:127.0.0.1", "/var/www/html/images/6081b3a39eed4.png"

<br/>
<b>Warning</b>
:  getimagesize(/var/www/html/images/6081b451efc1b.png): failed to open stream: Permission denied in 
<b>/var/www/html/libraries/src/Helper/MediaHelper.php</b>
 on line 
<b>78</b>
<br/>

System information (as much as possible)

Additional comments