Element picker won't open on https://www.lavuelta.es/

[lvmm]

Prerequisites

• [x] I verified that this is not a filter issue
  • Filter issues MUST be reported at filter issue tracker
• [x] This is not a support issue or a question
  • Support issues and questions are handled at /r/uBlockOrigin
• [x] I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • Your issue may already be reported.
• I tried to reproduce the issue when...
  • [x] uBlock Origin is the only extension
  • [ ] uBlock Origin with default lists/settings
  • [ ] using a new, unmodified browser profile
• [x] I am running the latest version of uBlock Origin
• [x] I checked the documentation to understand that the issue I report is not a normal behavior

Description

Element picker won't open on https://www.lavuelta.es/

A specific URL where the issue occurs

https://www.lavuelta.es/en/

Steps to Reproduce

1. open https://www.lavuelta.es/en/
2. rightclick on the page and select 'block element' in the context menu OR click on the ublock icon and select element picker (pipette)

Expected behavior:

Element picker window opens

Actual behavior:

Nothing happens

Your environment

• uBlock Origin version: firefox-legacy-1.16.4.30
• Browser Name and version: SeaMonkey version 2.53.9 beta 1
• Operating System and version: Linux server 5.4.0-80-generic #90~18.04.1-Ubuntu SMP Tue Jul 13 19:40:02 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

[reallyuniquename]

Possibly an asset issue e.g. https://github.com/uBlockOrigin/uAssets/issues/7837#issuecomment-681976831

[JustOff]

I can not reproduce this issue on a new unmodified browser profile.