I routinely use the related links quick links feature on lightning pages in our custom app.  I like that you can hover over the quick link and it will show a few rows of the related list without leaving the view that you are on.   

Here's the weird problem - at random times the hover stops working. When I hover nothing happens other than a repeat of the link in a little box.  I tried three different browsers and a dozen different Orgs and its the same in all of them.  I tried it in Orgs without our app and in trailhead orgs and its all the same.  This goes on for days or even weeks and then it suddenly starts working again - for days or weeks but then stops again.    

Taking the challenge for the Getting Started With APEX triggers and found that the trigger code below did not work and had the stranger problem of Changing the Match_Billing_Address__c field to True whenever i tried to save an account.  After a few exasperating hours, i changed I (a.Match_Billing_Address__c=true) to  (a.Match_Billing_Address__c<>false) and it all started working and I passed the challenge.   I would be grateful for any explanation of this behavior.
 

trigger AccountAddressTrigger on Account (before insert, before update) {
    For (Account a : Trigger.new) { 
        If (a.Match_Billing_Address__c=true) {
        system.debug(a.Match_Billing_Address__c);
        a.ShippingPostalCode=a.BillingPostalCode;
    }    
    }
}

 

I routinely use the related links quick links feature on lightning pages in our custom app.  I like that you can hover over the quick link and it will show a few rows of the related list without leaving the view that you are on.   

Here's the weird problem - at random times the hover stops working. When I hover nothing happens other than a repeat of the link in a little box.  I tried three different browsers and a dozen different Orgs and its the same in all of them.  I tried it in Orgs without our app and in trailhead orgs and its all the same.  This goes on for days or even weeks and then it suddenly starts working again - for days or weeks but then stops again.