Unfortunately there's no nice way to fix this. There are two options I see:
1. Convert time values into numbers (hours or minutes)
You can use
TO_PURE_NUMBER(x) to convert a duration to a number, where the value
1 equals 24 hours. So to get hours you can use
24*TO_PURE_NUMBER(x) or for minutes use
Then when you create the histogram the y-axis will just be count and the x-axis will have those hours or minutes with a decimal part.
2. Build your own histogram using a bar chart
On a separate sheet build a table of bucket boundaries, then use
COUNTIFS to count the number of values in each bucket. This can look something like:
A2:A15 are the bucket boundaries. Then, format the bucket boundaries however you like and put the table into a bar chart.