If the issue is limited to one single table I'd check it's clustered key choice. Fragmentation is most often the results of page splits which are most often caused by sub-optimal clustered index key choice. If you manage to use a better key as clustered index, this might solve your fragmentation issue.

Also check fillfactor of the index. This will not avoid fragmentation but postpone it because a page can handle more inserts before a page split occurs

If fragmentation can be avoided, index rebuilds will also be postponed. Which is a good thing as well for your application as for your maintenance window.