Are those menus from FF or the site menus? Screen shot of the problem in question.

The menus are not in/part of Firefox.

Here is one site: https://parknationalbank.com/

I can't choose the "type of account" from the pull-down menu as the website requires. This problem only started when Firefox automatically upgraded to 58.0.1.

Another site is mychart.com, through my doctor's office, but the problem occurs after I log in. Again , this problem only started when Firefox automatically upgraded to 58.0.1.

The "ACCOUNT TYPE" control on the bank site is a basic HTML "select" control -- very nicely styled. Can you operate the more basic-looking select control on the right side of this page (usually says Volvo):

https://www.w3schools.com/tags/tryit.asp?filename=tryhtml_select

If select controls seem nonfunctional on all sites, there may be an issue with the overlay that holds the various options. Could you test two things with the keyboard:

(1) If you click the current value in the control and press Alt+down arrow, the options list should display. Does that work?

(2) If you click the current value and then press the up and down arrow keys on the keyboard, the value should change just as though you were moving the selection bar up and down in the (invisible) drop-down. Does that work?

If you got #1 - FAIL, #2 - SUCCESS, it sounds like a display issue with the overlay, but still not obvious what it is.

In case the Firefox 58 update caused an incompatibility with one of your extensions, could you test in Firefox's Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block (wanted) content (Adblock Plus, NoScript, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block (wanted) content.

• make sure your extensions and filters are updated to the latest version

There is Tracking Protection that can block (wanted) content, so check the location/address bar for special icons.

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

I have no add ons or extensions ... I've given up on them because Firefox can't deal with them and I had to add them with each Firefox update ...

I only have an ad blocker. I disabled it and it didn't solve the problem.

The other suggestion is pretty much greek to me. I'm not any kind of software writer. Just wanted to use Firefox, but seem to have to switch to Chrome.

MQ2000 said

The other suggestion is pretty much greek to me. I'm not any kind of software writer.

I don't think you need to know any HTML to try the steps I gave you, but you might have been put off by the first sentence. Don't be. If the phrase "select control" is disturbing, change it in your mind to "form drop-down". You can do this.

I have XP and Firefox 52.6 ESR and it didn't work for me either. I went to safe mode and they DID work! Then I removed ALL of the add ons cache and everything else and restarted (had to put start page back in...AND THE DAMN THING WORKS! I didn't want to go to chrome, I like Firefox....now I can KEEP it!