SecurityTokenExpiredException: IDX10223: Lifetime validation failed. The token is expired. ValidTo: 'System.DateTime', Current time: 'System.DateTime'

In an ASP.NET Core 5 project with RestAPI, I'm using JWT Bearer with tokens and refresh-tokens. I configured the startup like this:

var jwtSecretKey = Configuration.GetValue<string>("Jwt:Key");
var key = Encoding.UTF8.GetBytes(jwtSecretKey);

var tokenValidationParameters = new TokenValidationParameters
{
    SaveSigninToken = true,
    ValidateActor = true,
    ValidateIssuer = true,
    ValidateAudience = true,
    ValidateLifetime = true,
    ValidateIssuerSigningKey = true,
    ValidIssuer = Configuration["Jwt:Issuer"],
    ValidAudience = Configuration["Jwt:Audience"],
    IssuerSigningKey = new SymmetricSecurityKey(key),
    // set clockskew to zero so tokens expire exactly at token expiration time (instead of 5 minutes later)
    ClockSkew = TimeSpan.Zero
};

services.AddAuthentication(options =>
{
    options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
    options.RequireHttpsMetadata = false;
    options.SaveToken = true;
    options.TokenValidationParameters = tokenValidationParameters;
});

For generating the Tokens I used this code (Something to notice is I used UTC dates):

string validIssuer = _configuration["Jwt:Issuer"];
string validAudience = _configuration["Jwt:Audience"];
var jwtSecretKey = _configuration.GetValue<string>("Jwt:Key");
var issuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(jwtSecretKey));
var accessTimeout = _configuration.GetValue<int>("Jwt:MinutosExpiracionTokenAcceso");

DateTime fechaHoy = DateTime.UtcNow;
DateTime fechaExpiracionToken = DateTime.UtcNow.AddMinutes(accessTimeout);

var userRoles = await _userManager.GetRolesAsync(user);

var claims = new List<Claim>
{
    new Claim(ClaimTypes.Sid, user.Id),
    new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()) // (JWT ID) Unique Identifier for JWT, can be used to prevent the JWT from being replayed. Is best suited for refresh tokens
};

foreach (var userRole in userRoles)
{
    claims.Add(new Claim(ClaimTypes.Role, userRole));
}

var token = new JwtSecurityToken(
    validIssuer,
    validAudience,
    claims,
    fechaHoy,
    fechaExpiracionToken,
    new SigningCredentials(issuerSigningKey, SecurityAlgorithms.HmacSha256)
);

var refreshTimeout = _configuration.GetValue<int>("Jwt:MinutosExpiracionTokenAutorizacion");

var refreshToken = new RefreshToken()
{
    JwtId = token.Id,
    IsUsed = false,
    UserId = user.Id,
    AddedDate = DateTime.UtcNow,
    ExpiryDate = DateTime.UtcNow.AddMinutes(refreshTimeout),
    IsRevoked = false,
    Token = RandomString(25) + Guid.NewGuid()
};

await _unitOfWork.GetRepository<RefreshToken>().AddAsync(refreshToken);
await _unitOfWork.SaveChangesAsync();

var tokensDto = new TokensResponseDto
{
    Token = new JwtSecurityTokenHandler().WriteToken(token),
    RefreshToken = refreshToken.Token
};

return tokensDto;

I'm facing issues validating the token (_tokenValidationParameters are the same as used in startup):

var jwtTokenHandler = new JwtSecurityTokenHandler();
ClaimsPrincipal principal = null;
SecurityToken validatedToken = null;

principal = jwtTokenHandler.ValidateToken(tokenRequest.Token, _tokenValidationParameters, out validatedToken);

It's throwing the mentioned exception with no specific dates, no matter whether I use localtime such as DateTime.Now instead of UTC.

I tried by adding LifetimeValidator in TokenValidationParameters in startup like this:

LifetimeValidator = (DateTime? notBefore, 
                     DateTime? expires, 
                     SecurityToken securityToken, 
                     TokenValidationParameters validationParameters
                    ) => 
                    {
                        if (expires != null)
                        {
                            if (DateTime.UtcNow < expires.Value.ToUniversalTime())
                            {
                                return true; // Still valid
                            }
                        }

                        return false; // Expired
                    }

However, ValidateToken fails with this exception:

IDX10230: Lifetime validation failed. Delegate returned false, securitytoken: 'System.IdentityModel.Tokens.Jwt.JwtSecurityToken'.

Thanks for any help