Wkhtmltopdf Command Error: with Chart.js responsive: false option - ruby-on-rails

Question

I'm generating Charjs graphs in rails with wicked_pdf and wkhtmltopdf (ver 0.12.4). i've updated wkhtmltopdf gem from ver 0.12.3.1 to ver 0.12.4 because it uses a lot of RAM memory and takes too much time when generate long PDFs, but charjs graphs worked. Now, with the new version, occurs an error when responsive chart option is set to false:
When set it to true, there is no errors but it does not work, even if the parent block has width and height setting.
i don't know how to solve this with the newest version of wkhtmltopdf and gem downgrade isn't an option.
pls help.
i've tried by setting width and height to the parent container and chartjs canvas, more javascript_delay in wkhtmltpdf, no animations in charjs, onbeforeprint callback with recomended function by charjs doc
html
<div class="canvas-holder" style="width: 800px; height: 1200px;">
<canvas id="real-costs-bar-chart-1" width="800" height="1200" style="width: 800px; height: 1200px;"></canvas>
</div>
charjs code
var ctx = document.getElementById(canvas_id).getContext('2d');
new Chart(ctx, {
type: 'horizontalBar',
data: {
datasets: [{
label: 'Real',
data: data1,
backgroundColor: backgroundColor1,
borderColor: borderColor1,
borderWidth: 1
},
{
label: 'Proyectado',
data: data2,
backgroundColor: backgroundColor2,
borderColor: borderColor2,
borderWidth: 1
}
],
// These labels appear in the legend and in the tooltips when hovering different arcs
labels: labels
},
options:{
title: {
display: true,
text: title,
fontSize: 10,
fontColor: '#00397B',
lineHeight: 3
},
responsive: false,
legend:{
position: 'bottom',
fontSize: 10
},
scales: {
xAxes: [{
ticks: {
// Include a dollar sign in the ticks
callback: function(value, index, values) {
return 'USD ' + number_to_cl(value);
}
}
}]
},
tooltips: {
callbacks: {
label: function(tooltipItem, data) {
var label =
data.datasets[tooltipItem.datasetIndex].label || '',
value =
data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index];
if (label) {
label += ': ';
}
label += 'USD ' + number_to_cl(value);
return label;
}
}
}
}
})
wicked_pdf config
pdf = WickedPdf.new.pdf_from_string(
template,
pdf: "Report_#{cost_report_type}", javascript_delay: 2000,
header: { content: header, spacing: 10 },
footer: { center: 'Pagina [page] de [topage]', spacing: 5 },
margin: {
top: 35,
bottom: 15
},
encoding: 'UTF-8',
zoom: 0.8,
orientation: 'Portrait'
)