Unblocking scripts in the overview panel does not take effect until site cookies & data cleared

[SorrelArticulata]

Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
• This is not a support issue or a question. For support, questions, or help, visit /r/uBlockOrigin.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• uBO uses default lists and settings.
• using a new, unmodified browser profile.

Description

I browse the web with ublock origin set to block inline scripts, 1st-party scripts and 3rd party scripts. Re-enabling scripts in ublock origin for specific websites sometimes fails to work until a completely unrelated action is taken: clearing cookies and site data in Firefox.

• Turning uBlock off using the big power button does NOT fix the issue, the site continues to be broken.
• Using private mode (with extensions enabled) or creating a new Firefox profile does work around the issue (probably because they do not re-use the same cookies & site data).
• You cannot reproduce this problem on a website after performing the workaround. That website is fixed from then onwards.
• This problem only seems to trigger on websites I have not visited before (or in a very, very long time).
• This problem only sometimes triggers. On average I encounter it a few times per week. I am not sure if this is because the cause is intermittent or if it has some special unknown requirements (like certain CSP policies or 3rd party script execution styles).

There is a chance this is a Firefox bug, any advice on what further logs to collect or diagnosis methods would be appreciated. The bug occurs a few times a week for me, on both my desktop and laptop, so I am able to collect more data on random websites as they play up.

A specific URL where the issue occurs.

https://wiki.qidi3d.com/en/Q1-Pro

Example Steps to Reproduce

My default global permissions are to block all scripts:

Much of the web works well under these rules, but as you expect this also breaks some websites in varying amounts (in this particular example the entire page is blank without scripts):

On such sites I re-permit scripts again in ublock origin (grey boxes):

Normally I then refresh the page and the website immediately starts working, but not always:

It appears that scripts are still being blocked. This is the bug. This behaviour should not be occurring.

The workarounds that seem to work include:

• Switching to a private browsing session (with the same extensions installed, ublock remembers the new grey permissions so the site works instantly)
• Creating a new firefox profile, or
• Clearing site data and cookies for the affected website.

This last workaround looks like this in the Firefox GUI:

Sometimes Firefox does not show this UI feature because a site has not set any cookies. In these situations I work around this issue by manually setting a dummy cookie in the web developer tools. The UI then re-appears, using it then fixes the website.

After performing this workaround the scripts are finally permitted and the website starts working again:

(Notice the lack of content security policy errors in this last console screenshot. I'm lead to believe that they are the smoking gun left when uBlock blocks scripts? If not then please tell me)

Expected behavior

Per-website Ublock settings take effect without needing to clear site data & cookies.

Troubleshooting information

uBlock Origin: 1.70.0
Firefox: 150
filterset (summary):
 network: 172222
 cosmetic: 44573
 scriptlet: 36363
 html: 3701
listset (total-discarded, last-updated):
 added:
  ublock-annoyances: 4923-38, 2h.26m Δ
 default:
  user-filters: 317-6, never
  ublock-filters: 52324-69, 2h.26m Δ
  ublock-badware: 11178-29, 2h.26m Δ
  ublock-privacy: 4013-2, 2h.26m Δ
  ublock-unbreak: 2822-1, 2h.26m Δ
  ublock-quick-fixes: 473-13, 2h.26m Δ
  easylist: 94045-155, 2h.26m Δ
  easyprivacy: 55994-33, 2h.26m Δ
  urlhaus-1: 28770-11, 3h.26m
  plowe-0: 3517-1029, 8d.5h.16m
filterset (user): [array of 317 redacted]
trustedset:
 added: [array of 73 redacted]
switchRuleset:
 added: [array of 2 redacted]
hostRuleset:
 added: [array of 5503 redacted]
userSettings:
 advancedUserEnabled: true
 cloudStorageEnabled: true
hiddenSettings: [none]
supportStats:
 allReadyAfter: 189 ms (selfie)
 maxAssetCacheWait: 84 ms
 cacheBackend: indexedDB

[gothic-bum]

Test again by forcing a page reload that ignores cached content:

• Windows/Linux: Ctrl + Shift + R or Ctrl + F5
• MacOS: Command + Shift + R

[krystian3w]

For me, using the button from the uBo interface helps (since it does a hard refresh).

Theoretically you can permanently assign a hard refresh to F5 from about:keyboard.

[SorrelArticulata]

Ctrl+F5 indeed seems to work, I just tried a few dozen 'new' websites and managed to work around the problem twice using Ctrl+F5 (where ordinary F5 refresh did nothing). So this is a caching issue?

For me, using the button from the uBo interface helps (since it does a hard refresh).

Ah, I often don't use that button because it's only temporarily visible (if you close & open the ublock overpanel then it is gone). Interesting, I assumed it was only ever doing a normal refresh.

[uBlock-user]

So this is a caching issue?

Not an issue, by design, browser behaviour.