@User The additional problem is that sky130 mosfets are wrapped into subcircuits. My suspect is that if AS, AS, PD, PS etc are not given they are assigned to 0 in the .subckt->mos model mapping:
.subckt sky130_fd_pr__nfet_01v8_lvt d g s b
+
.param l = 1 w = 1 nf = 1.0 ad = 0 as = 0 pd = 0 ps = 0 nrd = 0 nrs = 0 sa = 0 sb = 0 sd = 0 mult = 1
msky130_fd_pr__nfet_01v8_lvt d g s b sky130_fd_pr__nfet_01v8_lvt__model l = {l} w = {w} nf = {nf} ad = {ad} as = {as} pd = {pd} ps = {ps} nrd = {nrd} nrs = {nrs} sa = {sa} sb = {sb} sd = {sd}
.model sky130_fd_pr__nfet_01v8_lvt__model.0 nmos
* DC IV MOS Parameters
+ lmin = 8e-06 lmax = 1.0e-04 wmin = 7e-06 wmax = 1.0e-4
+ level = 54.0
+ tnom = 30.0
+ version = 4.5
+ toxm = 4.148e-9