Gatwick Airport has said it had returned to "business as usual" and that it will finish its flight cap at the end of the month.
Hours after the positive announcement was made, 26 flights - 13 departures and 13 arrivals - had to be cancelled after not enough staff went in to work, the business said.
"Restrictions were put on the number of flights that can arrive into Gatwick due to late-notice staff absence in the airport's control tower," said a spokesperson for the airport.
"Some flights throughout the day may unfortunately be delayed or cancelled as a result.
"Gatwick would like to apologise for any inconvenience this will cause to our passengers."
Gatwick's boss had earlier said the airport was back to "business as usual" and would not need to extend its capacity restraints beyond the end of the month.
The company said normal operations have resumed following months of strain on airports and airlines across Europe.
The airport - which is London's second busiest - said in June that it was moderating the growth in the number of flights after major disruption over the Platinum Jubilee bank holiday.
Without constraints over the summer passengers would have experienced poor standards of service. Queues would have been long and many flights would have been delayed or cancelled at the last minute.
But with the school holidays coming to an end, the worst has passed.
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Chief executive Stewart Wingate said: "The unprecedented growth in traffic led to short-term operational issues in June; however, our decisive early action to limit the airport's capacity in the crucial school holiday period of July and August has ensured passengers have experienced reliable flight timetables over the summer months.
"We are now very much operating business as usual and do not see any reason to extend the capacity declaration."
He said the boom in demand for overseas travel has helped the airport bounce back from the pandemic.
In the second quarter of the year demand was at 74% of pre-pandemic levels, Gatwick said.
More than 13 million passengers travelled through the airport in the six months to the end of June. It now expects 32.8 million passengers to use the airport this year.
But this prediction could be hit by runaway inflation, which is pushing up costs and making people cut back on luxuries.
Revenue hit £291.5 million in the six months, while post-tax profit reached £50.6 million.
"We still have some considerable way to go, but strong demand has fast-tracked Gatwick's recovery from the pandemic, particularly in the last quarter since all UK travel restrictions were removed," Mr Wingate said.
"Air traffic volumes have reflected this strong passenger demand and have bounced back to around 75% of pre-Covid levels.
"Despite some broad economic uncertainty, we are also looking forward to a successful second half to the year, with new, exciting airlines and routes coming on stream and continuous improvement in the high service standards Gatwick is known for."
