You've already contributed (had contributed on your behalf) the full $3,450 that you are permitted for 2018, so you are not permitted to contribute any more to an HSA for 2018.
If the old employer reports only $1,062 with code W in box 12 of your W-2 from them instead of $3,450, you'll have to claim the $2,388 as a personal HSA contribution. If the employer does not require you to pay back to them the $2,388, the employer should include the $2,388 as part of your compensation for the year.
