Medium Term Lump Sum Investment

TLDR: €300K to invest at age 50 with medium horizon to maximise compound interest.

Am in fortunate position to have €300K to invest on foot of savings maturing and investment property sale. Current and short-term future needs covered: no mortgage, children education covered, DB pension on track (currently both 50 yrs), modest lifestyle.

Have sampled direct shares, managed funds, investment property, state savings, credit union as savings/investments at various times and all disappointing. All have delivered very little return. No ready appetite for further disappointment but open minded nonetheless.

Have managed fund now recommended to me but wary. Priorities are to retire at 60 and improve lifestyle. Welcome any advice.

Are you maxing your pension contributions with 30%

Thanks @moneymakeover - I'm public sector and my pension would fully max by 62 so covered there.