A320 pilot reported being assigned to an aircraft that had been previously returned to service after a lightning strike. During initial climb; engine instrument indications became erratic and the flight return to the departure airport.

Narrative

Flight with service to ZZZ [airport]; was scheduled to depart from ZZZZ [airport] at XA:43 local time. CA and FO arrived to the airport before report time (XZ:58) and the incoming flight was scheduled to arrive late. When incoming plane finally arrived; deplaning was completed and we had the chance to get to the plane; we were informed by the incoming flight crew that multiple ECAM failures were shown after landing and they suspected a lightning strike during the final approach so they were putting the note in the logbook and that can be checked out by local maintenance. Local Maintenance took control of the plane and performed multiple resets but they had no luck solving the issue. The plane was momentarily put on 'out of service' status and we were told that the flight was going to be cancelled. 10 minutes after; the CA received a call indicating that the plane was going to be repaired and we needed to stay at the airport. Around XF:30; we were called to get back to the plane and passengers were sent to board right after. Local operations and Operations Control were pushing our inflight crew to board even without CA 'ok to board' instruction given the circumstances. Maintenance was still on board working on tests to make sure everything was functional and the CA made an announcement to passengers stating that we were not taking a plane without making sure that everything was safe and working properly. The plane was finally repaired and after 6 hours total delay; it ended up with 2 MELs showing a SDAC 2 and FWC 2 deferred and the plane was authorized only for CAT I ops. CA and FO went over each MEL in detail and determined that everything was in compliance with the MELs. We started to prepared the cockpit for takeoff and everything was normal during taxi and takeoff roll. We were cleared to take off from RWY XX and follow the noise abatement procedures for the airport. FO was the PF and CA the PM. Then; during initial climb and about 1500 ft both pilots noticed multiple ECAM failures; caution warning and we noticed we lost EPR (Engine Pressure Ratio) 1 indication and ECAM instruction to shut ENG1 off but after checking temperature; N2 we noticed the engine was working properly. All the indications and alerts were coming in and out all the time and it was impossible to determine the root cause of the issue at that precise moment. PF leveled off at 3000 ft. and we decided we needed to get back immediately. FO remained as PF and PM requested an immediate return to the field due to multiple failure indications. We [advised ATC] and received instructions to make a right pattern to get back to RWY XX. During this time PF noticed ENG1 thrust was going up and down and decided to disconnect the auto thrust. That stabilized our speed control. During downwind; PM called inflight and gave them instructions for a code yellow preparation; made a PA to passengers advising we were returning to ZZZZ and advised dispatch. PM set up the approach for landing and PF focused on keeping the plane flying despite the multiple distractions from the ECAM indications. When we felt we were ready for the approach; we requested a right turn direct to ZZZZZ (IAF) for the RNP RWY XX. We were cleared for the approach and then cleared to land and PF hand flown the plane down to the ground uneventfully. Normal taxi to the gate was performed after touchdown. After that; local authorities and personnel approached to the plane and CA took care of the situation.