In all previous shutdowns, "nonessential" federal workers were sent home were eventually paid for their furloughed time off when they returned as a part of the deal that restored funding. Unlike the troops & "essential" workers who stayed on the job and received a "lump sum" (mandatory) payment when funding was restored for the work they did during the furlough, the payments to "nonessential" federal workers were discretionary by Congress - not mandatory - because they were furloughed in a non-pay status. Perhaps it wasn't fair to pay some for staying at home while paying others to do their work, but that's what happened for whatever prevailing "wisdom" - and I use that term very loosely - Congress chose & the President signed off on.
This time, military and some DOD civilians are being paid on time as usual. Other federal worker who are designated "essential" must work, but won't be paid until funding is restored. "Nonessential" federal workers have been sent home until funding is restored. Congress & the President may choose to pay "non-essential" federal employees for furloughed time off as they have in the past, but they are under no obligation to do so and some of the reporting has been that the situation is so acrimonious between the hard-liners in the parties that it might not happen this time - particularly with a long shutdown where retroactive pay for unworked time would be significant financial impact. So it could be different this time, and those likely to be harmed the most are lower level civilian federal employees who may live paycheck to paycheck and may be unlikely to have significant cash reserves to "tide the over".