Štilić were caretaker managers. On 31 December 2018, Amar Osim for a second time in his career came back to Željezničar and signed a three-and-a-half-year contract with the club. In Osim's first game after returning to the club, Željezničar lost against Radnik Bijeljina, making that 6 losses in a row, but in his second game against Mladost Doboj Kakanj, Željezničar beat Mladost and ended their 6-game loss run. 2020s: 100 years of the club The 2019–20 Bosnian Premier League season ended abruptly on 1 June 2020 due to the ongoing COVID-19 pandemic in Bosnia and Herzegovina, with Željezničar having to settle with a second spot on table. City rivals Sarajevo won the title even though Željezničar won six points from two derby matches played during the league season. In the 2019–20 Bosnian Cup, they finished at the semi-final stage as the competition was cancelled due to the pandemic. The 2020–21 season started strongly winning four opening matches, however their run in the 2020–21 UEFA Europa League was affected due to the pandemic. The first qualifying round match between Maccabi Haifa, originally scheduled to be played on 27 August 2020 was postponed due to five members from Željezničar's delegation testing positive for COVID-19 and the whole team being put into quarantine by the Israeli authorities. Originally six players earlier tested positive and did not travel, being left in Sarajevo. The team returned to Sarajevo before UEFA made a decision to finally play the match on 9 September at Sammy Ofer Stadium in Haifa. Željezničar traveled again but lost 1–3 (thus eliminated after revised rules due to the pandemic) after being in quarantine 9 days prior with little to no training and no competitive matches since shock loss at home to Mladost Doboj Kakanj in the 5th round on 21 August of the 2020–21 Bosnian Premier League season. In the middle of an eight game winless run in the 2020–21 league season, which had culminated with a home draw against Mladost Doboj Kakanj, Amar Osim was sacked by the club on 11 April 2021. After Osim got sacked on 11 April, three days later, on 14 April, Blaž Slišković was named as Željezničar's new manager. On 18 June 2021, after Slišković left the club, Croatian manager Tomislav Ivković became the new manager of Željezničar. In January 2022, after he left the club, Ivković was replaced by Edis Mulalić. Stadium The club had