Arriving in the Caribbean, Severn patrolled the waters of each British Overseas Territory in the region and was on standby to provide any support, ranging from disaster relief to tackling all forms of illicit trafficking.

[14] In April 2017, Severn was detached from fishery protection duties to escort the Russian Navy Ropucha-class landing ship Korolev through the English Channel.

[16][17] In March 2018, six months since decommissioning, the Ministry of Defence announced that £12.7 million had been allocated from the EU Exit Preparedness Fund to preserve Severn and her two sister ships, should they be required to control and enforce UK waters and fisheries following the United Kingdom's withdrawal from the European Union.

[18] In November 2018, defence secretary Gavin Williamson confirmed that Severn and her sister ships would be reactivated and "forward operated" from their affiliated ports.

[23] One of her first operational taskings since rejoining the fleet saw her shadowing Russian Navy destroyer Vice-Admiral Kulakov, patrol boat Vasily Bykov and their two support ships as they transited through the English Channel on 9 July 2020.

[24] On 6 May 2021, Severn was deployed to Jersey alongside HMS Tamar, another River-class OPV, after reports that fishing boats from France would blockade the ferry Commodore Goodwill from reaching the island at 6am.

[27] Severn was painted in a Western Approaches camouflage scheme in time for her recommissioning ceremony alongside HMS Belfast in the Pool of London on 28 August 2021.