The deadline to roll over an ordinary HSA distribution is the 60th day following the date of the distribution, subject to the limitation of one rollover in a 12-month period. For a distribution in March, that deadline would be sometime in May. The issue is still that the 2025 Form 1099-SA will show an return of contribution rather than an ordinary distribution, so rolling the distribution over will still likely require explanation to the IRS (and perhaps to the HSA custodian if they question the source of the rollover).
Changing line 9 to $6,300 doesn't make any sense to me if the code-W amount is $9,300 and you were actually eligible to contribute $9,300. I don't know how you would have changed line 9. I also don't know how it's possible for exactly $3,000 of a $9,300 contribution to your HSA to be an excess contribution under any circumstances other than your wife making a personal HSA contribution of $3,000 to her own HSA which you haven't mentioned.
I don't understand what you mean when you say that the amount on line 18 "became" $0. It should always have been $0 because you made all of your HSA contributions through your employer.
