Fault on shinyapps.io?

I'm getting the following intermittent warning from a {learnr} tutorial on shinyapps.io. The warning shows up on both the log and the user's browser. It's followed immediately by an error that doesn't appear in the log:

Error in value[3L] : parse error: trailing garbage
":{}, "value":["0.10.1"]}]}]} {"type":"list","attributes":{},

The "(right here)" caret points et the starting quote on "type".

I haven't seen this before, and there are 400 students using the tutorial each day for the past 3 weeks. I have no idea how to generate a reprex for this, so all I can do is report the error. My intuition says that shinyapps.io is reading some data from an SQL database and the database is returning invalid JSON. But just a guess.

Here's the preceding warning, which might, of course, be irrelevant.

2021-09-01T14:43:51.030333+00:00 shinyapps[4270461]: During startup - Warning messages:
2021-09-01T14:43:51.030335+00:00 shinyapps[4270461]: 1: Setting LC_CTYPE failed, using "C"
2021-09-01T14:43:51.030337+00:00 shinyapps[4270461]: 4: Setting LC_MESSAGES failed, using "C"
2021-09-01T14:43:51.030336+00:00 shinyapps[4270461]: 2: Setting LC_COLLATE failed, using "C"
2021-09-01T14:43:51.030337+00:00 shinyapps[4270461]: 3: Setting LC_TIME failed, using "C"
2021-09-01T14:43:51.030337+00:00 shinyapps[4270461]: 5: Setting LC_MONETARY failed, using "C"
2021-09-01T14:43:51.030337+00:00 shinyapps[4270461]: 6: Setting LC_PAPER failed, using "C"
2021-09-01T14:43:51.030338+00:00 shinyapps[4270461]: 7: Setting LC_MEASUREMENT failed, using "C"
2021-09-01T14:43:51.069336+00:00 shinyapps[4270461]: R version: 4.1.0