Give up tracker on an apt to move onto family home ?

In a dilemma at the moment at what to do, here is our situation and it would be great to get some feedback

Living in a 2 bed apt with 2 kids. Apt was bought in 2005 for 270k and have a tracker now at 1% with UB so very good tracker

Balance left currently is €172k
Currently on the market and the EA is hoping to get 160k. Offer currently at 152.
UB have offered the home mover mortgage so we hold the tracker plus a % increase depending on the LTV on the next house and then the new top amount is at a variable rate. Then after 5 years the tracker goes totally

We have savings of € 70k

Should we rent and get a new mortgage or sell ? Tracker does say it is on my Primary residence.

A broker has advised we can get a new mortgage with other banks for more money €400k and UB have approved us for €300k and the other banks will do a better rate again depending on LTV but in around 3.99 %

If we rent the apt it will get approximately €1000 a month in rent. Management fees €600pa

I should mention we have another apt in negative equity in Northern Ireland to the tune of £ 40k & on interest only

Don't really want 3 mortgages, both apartments were from our single days & now we just want a 4 bed family home

Sell the 1st apartment ? Stick with UB or go to a new bank ?

You clearly are an accidental landlord and don't want to be a landlord, so sell both apartments, clear negative equity with savings and get on with your life.

Rent and save as much as you can while you look for your forever home. You can rent a suitable home in the meantime.