Where should I invest my Lumpsum amount?

I have been investing in SIPs for about 7 years. Most of my portfolio was in Axis Large Cap, which I recently partially redeemed. Alongside that, I’ve been investing in Motilal Oswal Midcap for the past 7 months, and I also have Gold and Silver FoFs from ICICI and HDFC. I started a SIP in HDFC Flexi Cap too, around ₹15k per month.

Now I have around 5 lakhs lying around from the Axis Large Cap redemption that I’m planning to invest. My question is, should I put the entire amount into HDFC Flexi Cap all at once or invest it gradually, like test the waters first with a smaller amount? Is it even a good idea to put all 5 lakhs in a single flexi-cap fund, or should I start with something like 80k and see how it goes?

Horizon :- 5-8 years
Risk :- Moderate
Goal :-Wealth creation (super young, so I can stay invested long-term)
Allocation :- Motilal Midcap, Gold FoF, Silver FoF in roughly 50:25:25 ratio, and now starting HDFC Flexi Cap
Why these funds :- Midcap for growth, Gold/Silver for diversification, Flexi-cap to have a flexible fund that can shift between large, mid, small caps
App used :- Groww

I just want to decide whether I should invest my lumpsum amount at once or in small parts along with My sip In HDFC Flexicap fund. I want to keep Motilal Oswal as my XIRR is -28.77 right now and I don't want to sell my fund in soo much loss. Afterall it has been only 7 months.