The link below suggests the 2019 figure was 718 (full year) and 534 to the end of September. This year to the end of September the number is 530.
Males YTD (2020) is 391, that seems to be where the 391 figure comes from. Last year it was 399 to end of September. For women the figures were 139 this year - 135 last.
Definitely in males >70 or <18 the numbers are worse. YTD this year the numbers are the same as full year last year in both age groups (13 for <18 and 70 for >70), but the 18-24 age groups seems lower this year, so I'm not sure how they get to the idea highest increase in <24 age group (57 YTD this year vs last year 77 full year). It sounds like fitting figures to a pre-determined narrative. The story you quote sounds fake news to me.
Of course these figures only count (successful) suicides, not the unsuccessful attempts, which could paint a different picture.