Did you thin the first coat?
Looks to me like tooo thick emulsion has been used to try and fill, this usually causes the mudcrack and agree, usually sorted with solvent undercoat as mentioned above.
I Never! not! ever! line with the aim of filling alll those joints, Butt, and just fill where the joints have wondered slightly. I tend to use a medium strength ready mixed adhesive nowadays, Its more pricey but saves on time and dries out quicker and more reliable when emulsioning over (joints wont lift)
I thin the first coat to seal/ prime then second coat bit more round. (thicker). Normally just two coats suffice.
god luck
Looks to me like tooo thick emulsion has been used to try and fill, this usually causes the mudcrack and agree, usually sorted with solvent undercoat as mentioned above.
I Never! not! ever! line with the aim of filling alll those joints, Butt, and just fill where the joints have wondered slightly. I tend to use a medium strength ready mixed adhesive nowadays, Its more pricey but saves on time and dries out quicker and more reliable when emulsioning over (joints wont lift)
I thin the first coat to seal/ prime then second coat bit more round. (thicker). Normally just two coats suffice.
god luck