Failure concatenated animations

Questions
1

Hello everyone, when you make a concatenation of animations of a .glb file, it fails in the connections between them. The idea is to have 3 animations, 1 input, another output, and 1 in the middle that is repeated, performed the glb in blender. Mainly, the scheme is as follows:

clip1: Frame (1.80)
clip2: Frame (80,200)
clip3: Frame (200,280)

Where frame 1 = 280, 80 = 200.

This is repeated constantly

the code is:

mixer = new THREE.AnimationMixer( mesh );
var anim = gltf.animations; 
var start = THREE.AnimationClip.findByName( anim, 'Entrada' );
var repeat = THREE.AnimationClip.findByName( anim, 'Repeticion' );
var end = THREE.AnimationClip.findByName( anim, 'Salida' );

 if (anim.length>0){
    var contador = 1;
    var actionstart = mixer.clipAction( start );
    var actionrepeat = mixer.clipAction( repeat );
    var actionend = mixer.clipAction( end );
    
    actionstart.repetitions = 1;
    actionend.repetitions = 1;

    actionstart.play();
    actionrepeat.play();
    actionend.play();

    mixer.addEventListener( 'finished', ( event ) => {
       console.log('Finished animation:' + contador,event)

        if(contador == 1){
            actionrepeat.reset();
            actionstart.crossFadeTo(actionrepeat, 0);
            actionrepeat.repetitions = repe;
        }
        if(contador == 2){
            actionend.reset();
            actionrepeat.crossFadeTo(actionend, 0);
        }
        if(contador == 3){
            actionstart.reset();
            actionend.crossFadeTo(actionstart, 0);
            contador = 0;
        }
        contador+=1;
    });
};

});

The fault seems to be that the animation is from frame 1 and when making .reset (), frame 0 is rendered first, therefore an image appears with the .glb in the position without animation and produces a jump in the image, It is not continuous between the different clips.

I hope I have explained myself, and if you could help me with any solution it would be helpful.
Regards, and thank you very much

2

Any ideas?