Package amsmath Error: Multiple label's: label '{33}' will be lost.

begin{align}
label{33}
begin{split}
alpha_{ng}^{min}-alpha_{ng}^{max}+gamma_nleq C_{ng}forall ginOmega^{G-n},forall ninOmega^N
end{split}
label{34}
begin{split}
beta_ell^{min}-beta_ell^{max}+frac{epsilon_ell^{min}}{beta_ell}-frac{epsilon_ell^{max}}{beta_ell}-gamma_{n}=0
forall linOmega^Lmid textit{FB}(ell)=n
end{split}
\
label{35}
begin{split}
&beta_ell^{min}-beta_ell^{max}+frac{epsilon_ell^{min}}{beta_ell}-frac{epsilon_ell^{max}}{beta_ell}+gamma_{n}=0\
forall ellinOmega^Lmid textit{TB}(ell)=n
end{split}
\
label{36}
begin{split}
&-smashoperator{sum_{substack{ ell inOmega^Lst\ textit{FB}(ell)=n}}}epsilon_ell^{min}+smashoperator{sum_{substack{ ell inOmega^Lst\ textit{TB}(ell)=n}}}epsilon_ell^{min}
+smashoperator{sum_{substack{ ell inOmega^Lst\ textit{FB}(ell)=n}}}epsilon_ell^{max}-smashoperator{sum_{substack{ ell inOmega^Lst\ textit{TB}(ell)=n}}}epsilon_ell^{max}
+\delta_n^{min}-delta_n^{max}=0~~forall nin Omega^N
end{split}
\
label{37}
&gamma_n leq textit{VOLL}_n~~forall ninOmega^N\
label{38}
&bar{D}_{n}-widehat D_{n}leqwidetilde D_{n}leqbar{D}_{n}+widehat D_{n}\
label{39}
&sum_{ ninOmega^N}|frac{widetilde D_{n}-bar D_{n}}{widehat D_{n}}|leqtextit{DR}
%end{flalign}
\
label{40}
begin{split}
&alpha_{ng}^{min},alpha_{ng}^{max}geq 0quadforall g in Omega^{G-n},forall n in Omega^{N};\
beta_ell^{min},beta_ell^{max},  epsilon_ell^{min},epsilon_ell^{max}geq 0quadforall l in Omega^{L};\
delta_n^{min},delta_n^{max}geq 0quadforall n in Omega^{N};
gamma _n in Rquadforall n in Omega^{N};\
bar{D}_{n} in Rquadforall n in Omega^{N}\
end{split}
end{align}

begin{align}
label{33}
begin{split}
alpha_{ng}^{min}-alpha_{ng}^{max}+gamma_nleq C_{ng}forall ginOmega^{G-n},forall ninOmega^N
end{split}
\
label{34}
begin{split}
beta_ell^{min}-beta_ell^{max}+frac{epsilon_ell^{min}}{beta_ell}-frac{epsilon_ell^{max}}{beta_ell}-gamma_{n}=0\forall linOmega^Lmid textit{FB}(ell)=n
end{split}
\
label{35}
begin{split}
beta_ell^{min}-beta_ell^{max}+frac{epsilon_ell^{min}}{beta_ell}-frac{epsilon_ell^{max}}{beta_ell}+gamma_{n}=0\
forall ellinOmega^Lmid textit{TB}(ell)=n
end{split}
\
label{36}
begin{split}
-smashoperator{sum_{substack{ ell inOmega^Lst\ textit{FB}(ell)=n}}}epsilon_ell^{min}+smashoperator{sum_{substack{ ell inOmega^Lst\ textit{TB}(ell)=n}}}epsilon_ell^{min}
+smashoperator{sum_{substack{ ell inOmega^Lst\ textit{FB}(ell)=n}}}epsilon_ell^{max}-smashoperator{sum_{substack{ ell inOmega^Lst\ textit{TB}(ell)=n}}}epsilon_ell^{max}
+\delta_n^{min}-delta_n^{max}=0~~forall nin Omega^N
end{split}
\
label{37}
&gamma_n leq textit{VOLL}_n~~forall ninOmega^N\
label{38}
&bar{D}_{n}-widehat D_{n}leqwidetilde D_{n}leqbar{D}_{n}+widehat D_{n}\
label{39}
&sum_{ ninOmega^N}|frac{widetilde D_{n}-bar D_{n}}{widehat D_{n}}|leqtextit{DR}
%end{flalign}
\
label{40}
begin{split}
&alpha_{ng}^{min},alpha_{ng}^{max}geq 0quadforall g in Omega^{G-n},forall n in Omega^{N};\
&beta_ell^{min},beta_ell^{max},  epsilon_ell^{min},epsilon_ell^{max}geq 0quadforall l in Omega^{L};\
&delta_n^{min},delta_n^{max}geq 0quadforall n in Omega^{N};
gamma _n in Rquadforall n in Omega^{N};\
&bar{D}_{n} in Rquadforall n in Omega^{N}\
end{split}
end{align}

begin{align*}
x &= 1 \
x &= 1  label{EQ:a2}
end{align*}

begin{align}
x &= 1 \
x &= 1  label{EQ:b2}
end{align}

begin{align}
x &= 1 label{EQ:c1}\
x &= 1 label{EQ:c2}
end{align}

begin{align}
x &= 1 label{EQ:b1} \
x &= 1 label{EQ:b2}
end{align}