Drop-downs not always displaying correctly

[mrgillly]

I have an app that is a request portal, and each week, about 100 new requests are submitted.  For the most part, the app is rock solid, stable, and works very well.  

When users create a new request, at the top of the form is a drop-down that contains a list of customers, and right after that is a drop-down showing the list of services that my team provides.  My issue is that, occasionally, every 10 or so days, I'll encounter a user who loads the request page and both drop-down boxes aren't displaying correctly.  The drop-down that lists the customers is completely blank, and the drop-down that lists the different services only shows one option, which is "1" (the Key for the first entry in the list).

This isn't tied to a single user, and occurs at different times of the day as well, making it even more difficult to troubleshoot.  Since this happens so infrequently, I have no idea what the issue could be, but it does mess up the table showing the different services. 

Any help would be great!  Thanks in advance.

[Steve]

I'd guess it's caused by intermittent connectivity problems, which is just the nature of the beast.

[mrgillly]

Thanks, Steve.  That's a bummer.  Nothing I can do to help alleviate the issue?

[Steve · Accepted solution]

In an ideal world, you would engage Support and they'd review recent occurrences for commonalities and patterns and propose some response. But with Google Support, I would expect no effort.

Things you might look at:

• Are the affected users in particular countries or regions versus users that are not affected? If yes, the problem might be tied to the regional Google infrastructure they're being directed to. You'd have to engage Support for help with this.
• Are the affected users using VPNs? Could the VPN be unstable? This is not an AppSheet issue.
• Are you using partitions? If so, could the affected users be using a partition served from a less-reliable source?
• Are you using private tables? If so, don't.
• How is Blank value comparison mode configured? If Legacy, expressions can produce very unexpected results if your data contains blank values.
• Review the security filters of the involved tables for borderline conditions, such as time and date conditions that may not handle day-, week-, month-, or year-changes well.
• Review partition expressions similarly.
• And slice row filter expressions.
• And Valid if and Suggested values expressions that generate the affected drop-downs.

[mrgillly]

Thanks again, Steve.  I don't have a lot of those enabled, so I'm thinking there isn't much I can do, and like you said in the first post, just chalk it up to the nature of the beast.  Thank you so much for your input!