The return of fans on Saturday was overshadowed by players at Millwall and Colchester being booed as they took a knee.
Supporters were back at The Den for the first time since February 29 after London was placed in tier two of the current system of coronavirus restrictions, but an incident ahead of the 3pm kick-off against Derby took centre stage.
Some of the 2,000 Millwall fans booed when players from both sides took a knee before the Sky Bet Championship match, which the visitors won 1-0.
It was a similar story later in the day when Colchester hosted Grimsby in front of close to 1,000 spectators at the JobServe Community Stadium.
Ahead of kick-off, when both players of the League Two clubs decided to take a knee in support of the Black Lives Matter movement, a small number of the crowd were heard booing.
Callum Harriott's 56th-minute goal earned Colchester a 2-1 victory, but the attacker was left frustrated by the action of some U's fans.
He said on Twitter: "Absolutely disappointed today! Before kick-off taking the kneel in support of Black Lives Matter and hearing our crowd is BOOING. Ridiculous @ColU_Official."
A statement from the League Two club read: "Colchester United are fully behind any and all of our players and staff who take a stand against any form of discrimination in football, sport and life.
"We also condemn the behaviours of any supporters that actively voice opposition to those activities."
Kick It Out chair Sanjay Bhandari had applauded the players of Millwall and Derby for "defying the hate shown by some fans" at The Den.
In a statement to the PA news agency concerning that incident, he said: "We are saddened by the behaviour of fans booing the players taking the knee today at Millwall.
"What this demonstrates is that players are right to continue standing up to discrimination, whether that is through taking the knee or speaking out.
"The fight for racial equality continues and we will continue to work closely with clubs across the country to tackle discrimination in all its forms.
"We urge the players to continue using their platforms and their voices to support this fight.
"We applaud the players of Millwall and Derby for taking a stand and defying the hate shown by some fans today."
The Football Association condemned the behaviour of fans at The Den in a statement published before Colchester's game with Grimsby got under way.
It read: "The FA supports all players and staff that wish to take a stand against discrimination in a respectful manner, which includes taking of the knee, and strongly condemns the behaviours of any spectators that actively voice their opposition to such activities."
Derby forward Colin Kazim-Richards made his feelings about the booing clear after the match in south London.
He tweeted: "Having to say this is a pain but I'll say it every single damn time this is why I STAND and STAND PROUD and I have to say every single person involved with @dcfcofficial did too made me proud to wear this shirt with the boys today!!! Absolute disgrace.."
Millwall manager Gary Rowett, who saw Jason Knight grab Derby's winner, expressed his disappointment at the incident, but said his players were concerned that taking the knee was in danger of becoming an empty gesture.
He said: "The players have released a statement together and said they don't support it (taking the knee) as a political message but support anti-discrimination.
"Moving forward, like a lot of clubs, they would prefer not to take the knee and actually enact change.
"They want to be proactive rather than it being a gesture which a lot of clubs are now saying is perhaps empty.
"That's not my consideration, but they now feel that gesture is in danger of being empty."
The EFL later signalled its continued support for clubs and players who wish to take the knee.
A statement said: "The EFL continues to support any individual player, players and clubs who choose to 'take the knee' in support of tackling inequality in society.
"We are disappointed that a small group of supporters have today chosen to voice their opposition to such activities directly aimed at raising awareness of the fight against racism.
"Discrimination in any form is not welcome and we remain committed to working with our clubs, including Millwall who undertake a significant amount of work on equality and inclusion initiatives, as we continue with our collective objective to eradicate all types of prejudiced behaviour, ensuring the EFL is an inclusive and diverse environment for all."