This error seem to be intermittent: for me, notifications sometimes work, but mostly they don't work:
All platforms (Desktop Chrome, mobile Safari, mobile Orion)

PaginatedListState.ts:96 TypeError: Cannot read properties of undefined (reading 'split')
at e.<anonymous> (index.tsx:42:39)
at forEach.t.<computed> (extend.ts:39:16)
at forEach.t.<computed> [as badges] (extend.ts:37:41)
at NotificationList.js:105:63
at Array.map (<anonymous>)
at NotificationList.js:104:23
at Array.map (<anonymous>)
at n.content (NotificationList.js:77:31)
at n.view (NotificationList.js:27:57)
at Function.a (render.js:30:16)
a @ mount-redraw.js:15
(anonymous) @ mount-redraw.js:25
requestAnimationFrame (async)
u @ mount-redraw.js:23
e.parseResults @ PaginatedListState.ts:96
Promise.then (async)
e.loadNext @ PaginatedListState.ts:73
n.load @ NotificationListState.ts:29
(anonymous) @ mobileChanges.tsx:32
forEach.t.<computed> @ extend.ts:86
O.handleEvent @ render.js:888
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