When I create a new panel, the old panel data cannot be refreshed?

[hl0709]

old panel
html：Value : Test
Script：html.querySelector('#myval1').innerHTML=ctxt.data.series[0].fields[1].values.buffer[0]

new panel
Value : Test
Script：html.querySelector('#myval2').innerHTML=ctxt.data.series[0].fields[1].values.buffer[0]

TypeError: Cannot set properties of null (setting 'innerHTML')

How can I solve it