Here is the sample that displays the chart appropriately (See Below). You can find this information in the Charts wiki
Belchertown Charts Documentation · poblabs/weewx-belchertown Wiki (github.com)If you still need assistance, we are going to need a copy of your graphs.conf file in the /skins/Belchertown folder of your WeeWx installation.
[raintotals]
title = Rain Totals by Month
show_button = true
button_text = Rain Totals
type = column
time_length = all
aggregate_type = max
aggregate_interval = 86400 # 1 day
[[rainmonthtotals]]
title = Historical Rain Totals By Month
subtitle = Rain Totals for All Months for All Time
xAxis_groupby = month
xAxis_categories = 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'
[[[rainTotal]]]
name = Rain Total