Hi, if you are running in consistent Private Mode or have Turned on Tracking Protection to Always then you will be in Private Mode with just a Regular Browser. Change setting back to Only in Private Windows.

• https://support.mozilla.org/en-US/kb/tracking-protection

If your Cookie settings are too strict like not allowing 3rd party cookies you can also have issues.

• https://support.mozilla.org/en-US/kb/websites-say-cookies-are-blocked-unblock-them

Please let us know if this solved your issue or if need further assistance.

Don't use Private Mode or have tracking protection on.

Here's an article about possible causes for images not to appear in a page, in case you haven't already seen it while submitting your question:

Fix problems that cause images to not show