lubuntu focal daily; using grub menu at boot freezes system

[Chris Guiver]

reported against syslinux as iso.qa.ubuntu.com says to

Lubuntu focal daily booted on
- sony vaio svp112a1cw (i5-9400u, 4gb, intel haswell-ULT)

to test for wifi bug..

On initial boot I get the grub options (which include safe graphics, OEM)..

** Expected outcome

I can use arrow keys to scroll up & down the boot options (start lubuntu, safe graphics, OEM etc)

** Actual outcome

If i use the arrow keys at this point - the system freezes and doesn't recover. It was left sitting for ~20 mins at longs, at least 4 attempts.

** Additional testing

If i boot the same ISO (thumb-drive) on another box, eg. I tested using
- hp dc7700 (c2d-e6320, 5gb, nvidia quadro nvs 290)
- hp 8200 elite sff (i5-2400, 8gb, nvidia quadro 600)

no issue was discovered (though dc7700 is BIOS, the sony is uEFI, but hp 8200 is also uEFI though different firmware etc)

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: syslinux 3:6.04~git20190206.bf6db5b4+dfsg1-2
ProcVersionSignature: Ubuntu 5.8.0-52.59~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-52-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.17
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445.1
CurrentDesktop: LXQt
Date: Sun May 9 03:30:01 2021
LiveMediaBuild: Lubuntu 20.04.2 LTS "Focal Fossa" - Release amd64 (20210508)
SourcePackage: syslinux
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1927844