I don't know where else to get Garmin's eyes on the issue except here, but it's a nice feature that I use a great deal to find past activities for sharing, comparison, etc.
Errors from my console.log
common.js?bust=3.13.3.0:351 GET connect.garmin.com/.../marine_main_en.properties 404 ()
send @ common.js?bust=3.13.3.0:351
ajax @ common.js?bust=3.13.3.0:351
loadAndParseFile @ common.js?bust=3.13.3.0:351
$.i18n.loadPropertyFiles @ common.js?bust=3.13.3.0:351
loadPropertyFile @ common.js?bust=3.13.3.0:351
(anonymous) @ common.js?bust=3.13.3.0:351
(anonymous) @ common.js?bust=3.13.3.0:351
d.each.d.forEach @ common.js?bust=3.13.3.0:351
load @ common.js?bust=3.13.3.0:351
initialize @ common.js?bust=3.13.3.0:351
t.Router @ common.js?bust=3.13.3.0:351
i @ common.js?bust=3.13.3.0:351
(anonymous) @ activities:75
execCb @ require.js?bust=3.13.3.0:7
check @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
y @ require.js?bust=3.13.3.0:7
emit @ require.js?bust=3.13.3.0:7
check @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
y @ require.js?bust=3.13.3.0:7
emit @ require.js?bust=3.13.3.0:7
check @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
(anonymous) @ require.js?bust=3.13.3.0:7
y @ require.js?bust=3.13.3.0:7
emit @ require.js?bust=3.13.3.0:7
check @ require.js?bust=3.13.3.0:7
enable @ require.js?bust=3.13.3.0:7
init @ require.js?bust=3.13.3.0:7
g @ require.js?bust=3.13.3.0:7
completeLoad @ require.js?bust=3.13.3.0:7
onScriptLoad @ require.js?bust=3.13.3.0:7
prototype.js:1527Uncaught TypeError: Failed to execute 'evaluate' on 'Document': parameter 2 is not of type 'Node'.
at HTMLDocument.document._getElementsByXPath (prototype.js:1527)
at klass.findElements (prototype.js:2849)
at Function.findChildElements (prototype.js:3418)
at $$ (prototype.js:3444)
at Object.load (scriptaculous.js?load-effects:57)
at scriptaculous.js?load-effects:68