Hi there,
Open jltimeline.html.twig line 388 change
<div class="jl-grid jl-grid-collapse jl-flex-{{particle.c_maxwidth_alignment}} jl-visible@s" jl-grid>
to
<div class="jl-grid jl-grid-collapse jl-flex-{{particle.c_maxwidth_alignment}} jl-visible@s" jl-grid>
Next line 683 remove
{{item_switcher}}
NOTE: You need to custom css code for the responsive item if any.
Thanks