A Revolut feed usually stops in Xero for one of four reasons: the account is personal rather than Business, a currency account has no matching Xero bank account, the feed was connected after the period you're trying to reconcile, or the integration was disconnected on the Revolut side. Only the last one is a reconnect away, and even that leaves the gap it stopped over.
Xero publishes feed status in three separate places and they answer three different questions. The Xero status page tells you whether Xero itself is up, the bank feed disruptions page tells you whether your bank is in a known outage, and View Status Updates on the bank account tells you what Xero thinks about your feed in particular. This page isn't a live status board and can't be, so if you're checking right now, open the two Xero pages linked below first.
You can still add the account. In Xero, go to Accounting, then Bank accounts, click Add bank account and start typing the bank's name. If it isn't there, or it appears with a Manual upload label, no feed is available and you add the account through Add without bank feed instead. The account then works like any other, except that statement lines only arrive when somebody imports a file, as CSV, OFX, QBO, QFX or QIF. The import itself takes a minute. What it never does is tell you the file was complete, that the closing balance agrees with the bank's, or that the amounts are the right way round.
Yes, through Xero's Bank Feeds API, but Xero does not hand that out with a developer account. An application has to be approved by Xero before it can open a feed connection against a bank account and post statement lines to it. Anything without that access can read your statement and give you a file back, and a file goes into Xero as an imported statement rather than as a feed.
Stripe records sales gross and pays out net of fees days later, so the bank feed shows one figure and your sales show another. The fix is to treat the Stripe balance as its own Xero bank account: sales and fees land there, and the payout reconciles against the bank as a transfer.
Export the Revolut account statement as CSV for a clean import, or as PDF if you need the certified version. Xero's importer needs a date, a description and a single signed amount, so Revolut's separate Fee column and its REVERTED rows both have to be resolved before the file will balance.
Xero's manual import accepts CSV, OFX, QBO, QFX and QIF files, not PDF or Excel. It needs a date, a description and either one signed amount or separate debit and credit columns. It verifies no running balance, catches no sign error, and imports a period rather than establishing a feed.
A Wise feed usually stops in Xero for one of four reasons: someone disconnected it, the currency balance has no matching Xero account, the period you want predates the feed's twelve-month backfill, or the account is a personal Wise account, which cannot connect at all. Only the first is a reconnect away.
A Xero bank feed usually stops for one of four reasons: the open banking consent expired, the provider is having an outage, something changed at the bank, or the account was never eligible for a feed. The first three are fixable from inside Xero. The fourth is not, and no amount of reconnecting will change it.